No apologies needed.
When you have an UTH attached, it is best to just clean where it sits. Once the Aspen is removed, you have several options.
First things first, however, I don't replace my Aspen (I use Sani Chips) but about once every 3 to 4 months. I can easily see the poop on the Sani Chips, it clumps easily, and spot cleaning is a breeze.
Back to the subject. The cheapest way to go is a 10% bleach to water solution in a spray bottle. Spray the tank down, let sit for 5 to 10 mins, then wipe down. A quick spray rinse, another wipe, let sit for 30 mins just to be safe (Bleach evaporates very quickly) and you can put in new aspen and your snake.
Others use Vinegar - very good at disinfecting. Still others use store bought reptile enclosure cleaners (I find these over priced).
Generally speaking, though, the tank doesn't have to be sanitized every time the substrate is cleaned. If there is poop stuck on the bottom or sides, just spot sanitize that area.
This has always worked for me.