Aspen is a good bedding, I have never had a problem with cleaning it. I actually noticed that cleaning is a bit easier, the aspen seems to kind clump together when it is soiled. I used paper towels and newspaper for a bit but noticed that when it gets soiled the liquids quickly spread all over the paper towel, and by spread i mean get adsorbed. When you use the aspen it just stays in one general area and just just spot clean it.

You do need to change it every so often to keep everything clean. Also noticed that the smell overall in my snake room is much less when I am using aspen.

Don't use carpet under the bedding, first there is no need and second is that it is way too much insulation.