Looking to see if there's stuff I've missed which doesn't get posted on here.
I know of:
Can-Am/BG East, loads really: loads of oil (Czech Tag Teams are particularly good), one mud (mud madness), shaving cream (Todd Maine's Intense Initiation, Cody's Revenge, Supermatch 4), some paint (Supermatch 23 or 24). The Hard Heroes series has plenty of shaving cream, mud baths, some gunging (The Verdict).
There's also NakedKombat with some mud and oil. Tend to find that a little violent.
Something called Wide Nude World of Sports with some excellent mud at the end--which is the only decent bit. A little bit of mud at the beginning of Gimme Five (Next Door Studios).
Very thick mud in The Main Attraction Vic Summers Image Studio, may be something else.
A Dickdorm thing in chocolate pudding which is excellent.
UK Hotjocks, 'grappled' in gunge.
'Beach and Boat' has a bit of mud; quite good..
Massage: Next door buddies, Nuru oil massage.
Something called Club Dean, Dean & Duke featuring a *lot* of whipped cream.
Can-am. Many foodstuffs (American Porn Star)
There is also some mud stuff that gets caught up in the watersports and shit scene, which isn't my bag. (and is not to be promoted here, I see!)