Been trappin since i was little, use to hitch a ride in my granpa's packbasket.
I use waxed dirt mostly for my yote/fox sets here in MI due to the freeze/thaw moisture issue.
gotta love a educated fox, you'll have to make sure you got a good clean set in front of the dirty one he's flipping and force him to walk thru your clean set.....i'd make a big blown out dirt hole set at the dirty one he's flipping (like something got in there and tore it up) and use his curiousity against him!
We finally shook our super cold weather, so i'll be out after the mink this weekend!