Sharing your kink can be stressful, to be sure. Especially when it's something as unusual as WAM. When you have that conversation, what do you think would be the most helpful accessory, so to speak, in order to give them the best understanding of what it is you like?
I think that the "cultivated collection" is closest to the mark, because that will be tailored to what *you* like (rather than the rest of the UMD or a mainstream mention). There are enough sub-niches that it's best to avoid confusion. E.g. I prefer gameshow style WAM, where everyone is having fun; other people like BDSM humiliation with ball gags.
I have an 8 page document explaining WAM with a bit about my personal likes at the end. I let them read it and await in terror for the outcome. So far all good as I tend to pick very accepting people, but only some partners will do sploshing, I think that is a bit of a step for some.
No idea at this stage if it would be useful or not but I've added an 'introduce your gf to wam' session to my list of session choices to include a chat about it all from a female perspective - everything I love and why, and then a demonstration of all fave substances and a pie throwing lesson. I intend to make a short youtube video at some point too going over the basics.