So far, I've managed to gunge myself with:
- shaving cream
- whipped cream
- oatmeal
- pudding
- cake batter
- frosting
- s-lube
- j-lube
- natrosol
- MS gunge

I'm hoping to add mud/clay and nutella to the list at some point.

Underwear and speedos turn me on, too, so I will usually incorporate those as well. I maintain Swimdex, formerly the Men's Swimwear Database, https://swimdex.softr.app/

If you're going to add me as a friend, at least have a photo or video posted. I use UMD on my phone, so chat doesn't work.