I have read from previous users, it’s best to keep the genie
in the bottle, once is out it’s too late, you can’t put the genie
back in.
I'm not saying that doesn't ever happen, but I've read from more users where that didn't happen than did, by a long shot, and it's not the experience my wife and I have had. Our relationship is great, we're as strong as we've ever been, and we're both very glad we've taken this journey together. In fact, if your relationship fails because your partner values sex with someone else more than she (or he) values your relationship, maybe that relationship wasn't destined to succeed in the first place? I don't know, just a thought. Recommending you keep your partner from enjoying something he or she wants to try doesn't seem like the kind of advice that builds the strongest relationships either, to me.
My advice wasn't, "you should find a bull." My advice assumes the asker already evaluated his relationship honestly, is confident in his partner's commitment to him and the relationship, and they have decided to move forward together as a couple. There's a reason you don't see me answering in most "how do I get my wife to try this" threads. When I do, my answer is open communication and no pressure, ever. Don't "try to get" your partner to do anything.
But this person didn't ask how to convince his wife, and he didn't ask, "should we do this?" This person asked how to find bulls, and whether other people thought a guy he knows might be a good fit, so that's where my advice started. One-size-fits-all approaches to advice, like "you should/shouldn't try this," seldom turn out to fit all people, in my experience.