It depends on the dildo and the surface you're attaching it to. I have smaller tile (slightly under 4"x4") and it sometimes hinders the suction cup on my Vixen Creation's Leo. If it were a completely smooth surface, it would work way better. I know this because I've stuck it to the bottom of the tub and it works great. I am big on suction bases, because I really like shower play, so when I'm looking into a dildo, that's what I look for the in the review. There is a Tantus Suction Cup, that EF used to carry, that can be attached to a vibrating dildo that has a removable bullet. The reviews look great for it, and I'm looking into buying it. As, I said before though, it depends on the surface that you're trying to stick it to. Or at least that's what I've found in my experience.