I just do a soak by slowly pouring water over my Russian until the water is up to where the carapace meets the plastron. I use a soft toothbrush if there's caked on stuff on his plastron. Once in a while I use a little bit of coconut oil while he's still a little wet and then buff him up to dry with old dish towels. He doesn't seem to mind that. I've also used a little popsicle stick to gently scape off chunks of poop before his soak so I don't have to change the soak water right off the bat.
