Foot Fetish (and what's in your camera bag) (Patreon)

I guess if you are into that kind of thing, this movie could be worth a lot.

I'm not.
However, the movie illustrates the non-camera thing I always have in my camera bag when going shooting on location:
Wet-wipes. 

Once you go into a dirty spot short of a proper washing room with running water and soap, this is the only thing that will save you.