Skittle doesn't have that much substrate as he tends to stuff it all in his tubes and then get stuck
(that was quite scary; good job I hadn't gone to bed!) so we give him enough to stay warm and cosy (and it is a fair bit) but not too much, so cleaning him out is cheap for us. I try and remember to take out the wet patches daily or every other day, but he poops everywhere - and I mean everywhere - so I can't "poo pick" so to speak. Therefore, once a week I empty his cages completely, spray everything, bin all substrate/food stashes/poo etc and give him fresh substrate (carefresh). I only leave the bedding/substrate in his tubes/tunnels and when I cleaned him out last night I left it in his bed chamber too as it looked relatively clean i.e. not much poo in there. Once put back in his spotlessly clean cages (he has 2 joined together by tubes) he did kinda run about as though to say
"where's it all gone?!" but he soon settled once he found the yummy treats scattered about (a generous pinch of dried mealworm/fruit/veg mix) and he's currently fast asleep in his little pink house, having moved from his tunnel, having moved from his bed chamber ... honestly, I wish I had so many places to choose to snooze in, haha.