I have a tiger pistol paired with a high-fin goby. I have never observed him cleaning, (and yes, I am known to watch my tank at night). He comes out with the goby at feeding time and pretty much spends most of his time bulldozing sand and snapping at any crab, snail or fish that gets too close to the burrow. They are scavengers, tho so I'm sure he wouldn't pass up the chance to snack on decaying matter in the sand, just don't expect one to do all the janitorial work in your tank.