We used to use aspen bedding as our substrate when we first started out, but when we rescused a Burmese with a resperitory infection 4 or 5 years back, he had trouble recovering with the added dust, having always been kept by his previous owner without anything.
Now days we use mostly paper towels, simply because they're a bit cheaper and more cost effective, and they don't have any dust, or real chance of getting stuck in anybodies mouth or eye or anywhere else they can think of to make my day more interesting
Only minor problem we have with them is that if you don't mist the cage every once in a while, there's a better chance you're reptile will have a bad shed, as paper towels are designed to suck up ALL the moisture
It's a good solution if you're running low on substrate and don't have the cash just yet to go buy a new bag when someone messes their cage.
That's just my two cents
Kind Regards,
Kylie Rae