The concept of getting wet or messy is not new to the mainstream public--not even the concept of getting aroused by it. The wammers' choice of substances is perhaps what raises the most eyebrows to the uninitiated.
For example, there is no shortage of fantasies--realized on television, in the movies, and even in an average person's mind--that focus on erotic whipped cream
play. Whipped cream bikinis, whipped cream blowjobs, or even just a dollop on a nipple ready to be licked off--it's nothing too out of the ordinary. Therefore, whipped cream can be considered a good "gateway" wam substance for a person who wants to introduce their partner into wam without freaking them out.
After using a "normal" amount of the substance in an encounter with your significant other, you may be able to eventually escalate it into a full-on, head-to-toe wamming session. Use of a gateway substance allows allow you to gauge the reaction of your partner, so you can tell if they are really enjoying it and accepting it, or if using a certain amount of these substances makes them uneasy, as if they are the unwitting participants in a weird fetish.
It may be slightly disingenuous, but you can use smaller amounts of a gateway substance with your partner to portray the idea that you are just now learning and discovering your own kinks, and that you want your partner to explore the boundaries with you. Depending on the nature of your wam preference, you may have your work cut out for you if you want to make the leap from slightly messy fun, to full-on, fully-clothed coverage while wearing wedding attire. If you prefer substances that make it harder to imply to someone that your fetish isn't uniquely kinky--such as baked beans
--then a gateway substance may help you break the ice, but you may have to be more gradual with introducing them.