Note for readers: This review will primarily be focused on the aesthetic value, usage as a soft packing harness, and how well it fits for my body type. If you are more interested in how it holds up during the real movement of strap-on sex, I warn you that this review isn't going to be a lot of help. Now you may continue.

The RodeoH briefs are best described by their own manufacturer, on this handy tag attached to their storage bag:
"RodeoHs are the new way to strap-on. Beyond being stylish and sexy, they are significantly more comfortable than any other harness on the market. Slip on like a pair of underwear and wear all day."

Basically, this is a harness for strap-on sex in the guise of a simple, comfy pair of briefs. No adjusting straps and buckles necessary here! These can be used for soft packing as well, and work very well for that.

As for using this in the tub, shower, or pool: I think this would work perfectly fine in water as long as you're not bothered by tight, wet briefs clinging to your body. There's no metal to rust or leather to ruin. I wouldn't take it in the pool unless you don't worry about chlorine's effect on the fabric quality.

According to the tags, this underwear harness is made from 95% cotton and 5% elastane. It feels like slightly stretchy cotton, like a lot of t-shirts are. It's soft, thick and quality material. I like it a lot and I think it's going to hold up well.

The waistband is wide elastic, printed with "rodeoH" in different shades of grey.
Waistband:

The underwear harness is pretty well made. Some of the stitching looked a little off and there were some loose threads but nothing glaringly obvious or anything that would harm the garment. The elastic is attached well as is the inner panel to keep the dildo in place. The bottom panel is thick and well-lined. I hate when underwear has a flimsy inner lining and nothing else, so the solid construction of the inner part here made me happy.

The biggest problem with these in my opinion is the fact that the o-ring is sewn in and not replaceable without ruining the underwear. It's an average size fitting toys at around 1 and 1/2" in diameter but I have found that I like o-rings a little on the larger size for the toy I'm trying to use it with so I don't feel like it's going to get stuck. The stitching around the o-ring is sturdy. You can manipulate the ring a little bit but it doesn't seem all that stretchy.

The look of these is awesome. The contrast of the lighter grey edging and red inner panel against the black underwear is a nice look. I was originally going to get the pair that is all grey since it's so discreet but I'm glad I went with this one, as it's a more sexy color combo.
Close-up of o-ring and one of the side openings of the front pouch, like men's y-front underwear:

The back of the inner pouch:

Back panel tucked down to show o-ring

I have a 28" waist and measure 38" at the thickest part of my bottom half. I ordered the 29" size knowing I would be wearing them low on my waist and hips where it's about 31". It fits perfectly. It's not too tight, isn't really stretching much on me, and also isn't too loose which is what I was most afraid of. It fits me like all my favorite men's underwear does and I feel very sexy in these. I carry most of my weight around my hips and thighs and I liked that these didn't dig into my thighs or hang around them with too much fabric either. There's nothing more confidence-boosting than wearing underwear that fits right and looks great, except knowing that the same underwear will also allow you to perform sexually the way you want to.

Unfortunately, these are not adjustable so if I ever gain or lose a significant amount of weight I'll have to buy a new pair. There's no velcro or straps to tighten/loosen the fit. Like other reviewers, I recommend ordering a size number about an inch or two lower than the measurement around where the waistband is going to be worn.

I first tried out the RodeoH's dildo-holding abilities with the rather small Spur, by Vixen Creations. At less than 1 and 1/4" in diameter, it's nowhere near the supposed maximum that this harness can hold. I assumed it would flop around in the ring despite its wide base. Not true! It stayed in place quite well considering its size and the movements I tested it with.

After that, I placed the larger O2 Mark by Tantus (1 and 3/8" in diameter) in the o-ring. I liked that, unlike with my harness featuring an exposed, metal o-ring, the knit material made sliding it in really easy. It was a perfect fit when it comes to size, but not so much when it comes to weight. It would hold in place fine when still as long as I kept the waistband as high and tight as it could go on my pelvis, but it definitely drooped from the weight. It stayed in place fairly well with limited movement but with any aggressive movements the base knocked around against me quite a bit. This prevented me from having any pleasurable pressure on my clit, though the placement of dildos in this harness is already a little too high for that. I would recommend using heavier dildos with positions that don't require a lot of movement on the giver's end.

Finally, I tested it with my x-small Mr. Limpy. This is where I got absolutely gleeful. I generally soft pack with tight underwear but this was better than any way I had worn it up until now. Placing the head and shaft through the hole positioned the balls against me in a way that was unnervingly right and awesome. I was concerned that it would fall out of the front pouch since it only has squishy balls and no real base to speak of, but after a while of dancing and swinging poor Mr. Limpy around I concluded that the likelihood of your packer taking a trip down your pants leg while wearing these is very small. It wanted to come out of the front hole more than the opening on the side, and the balls kept it from doing so. With a slightly larger packer like the Mr. Right, I don't think this would even happen at all. I wouldn't try to use a stand-to-pee device with rodeoHs because of how small the pouch is. It would be a little hard to maneuver the back panel down to line yourself up right without a mess.

So, in conclusion, it's great for light dildos, pretty darn decent for dildos close to the recommended size for the o-ring, and awesome for soft packing.

The little bits of care instruction on the garment tag and tag on the storage bag say that you can machine or hand wash these in cold water, and hang them to dry. Don't boil them, bleach them, or iron them.
These can be stored just like any pair of normal underwear you own. You can keep them in the included storage bag or just tuck them in a drawer or wherever you usually store toys.

The underwear came in a smell, drawstring fabric bag with "rodeoH" printed on it and an information tag. It also came with a metal dogtag necklace that also says "rodeoH."
I really liked the choices in packaging and promotional materials. The bag can be used for many purposes and the addition of a dogtag necklace appeals to my butch side. The only thing I could have asked for more was maybe some more instructions on how to wring the most life out of a pair, since rodeoHs are expensive for a pair of underwear which can wear out and what are essentially something a person could make at home with good sewing skills and a rubber o-ring.

I don't know if I'm the only person who had this issue, but my RodeoH underwear and storage bag smelled really strange. I can't quite place the scent. It's dissipated off the actual underwear harness with days of airing out but the bag still carries it pretty strong. It's not horribly unpleasant or anything, but it did bother me because it wasn't exactly a great smell either.