I've certainly heard of BDSM working effectively as therapy in a variety of ways. That said, there's no guarantee that your negative feels about this behavior will necessarily disappear just by seeing the same behavior in a BDSM context (even if you happen to enjoy it in the BDSM context). So, for instance, my partner might like when I slap her face during a scene, but that positive association in that particular context doesn't mean that she'd ever like it if I slapped her outside of a scene; she might very well love the activity in the context of a consensual, sexual BDSM scene and still find it disrespectful and hurtful outside of BDSM, because it lacks the crucial elements of context and consent. On the other side of things, I've found that playful name-calling in-scene--"slut," "bitch," and so on--has largely desensitized my partner to that sort of language out-of-scene, but only when it's still "playful"; I'm certain that angrily calling her a bitch would hurt her feelings no matter how many times she's enjoyed having that same word used when the intent was to turn her on or joke with her. Basically, it's impossible for positive in-scene associations to translate to out-of-scene contexts but it's certainly not going to work or make sense 100% of the time.

Really, the ideal scenario is for your husband not to do whatever it is in the first place so that you're not in the position of trying to figure out a way to cope with it. Whatever it is, though, it sounds as if you've communicated your opposition perfectly clearly, so it sounds like the ball's in his court on that one.