@Timtee It takes a bit of work to get going. I ended up just not using it in the end, mostly because I didn't feel like setting it back up for the endoskeleton version. Apparently I was already hitting the limit on how many "options" an avatar can have; one of the modules has an erection setting for the penis and it doesn't work as intended with the endo. Not a big deal though, not missing out on much.
It basically walks you through setting up the bug tail's shader to be translucent, and then setting up the fluid (visual + radial setting). I think it also has the fluid appearing in the balls/penis if the radial is set high enough, but you won't really need that much going on unless you're doing NSFW roleplays... or whatever people do with that. No judging.