I keep mine on aspen. I like paper towels better, but I've opened tubs too many times and found them laying in "snake soup." Mine must be incredible pee machines because I've put almost half a paper towel roll in a bin and had them soak it completely.
I have a spatula in the snake room dedicated to the task of removing any wastes that only require a spot cleaning. For total clean outs I dump the aspen in trash can, scrape it out with the spatula, rinse it out in the snower, then wipe it out with a paper towel. I spray it down with F-10 and let it dry. I have two extra tubs so that I can switch snakes out easier when I'm cleaning their bins.