I found a clip from a german newsreel I've not seen before of two women in swimsuits and white swim caps wrestling in some nice black sludge: https://progress.film/record/21675 You have to register to watch it (free) and it does have the site logo across it. But it's a new 'find' for me and is the sort of mud wrestling I like. I'd love to do this sometime, would dress up in bikini and white cap for a wallow in front of an audience