Should I clean air filter box with a wet towl?
 

Should I clean inside air filter box when replacing the filter with a wet paper towl ?

If the box is super-dirty go ahead and clean it. It won't hurt.

I'd use a clean damp rag instead of a paper towel and then wipe it dry.

Ok, btw what brand to get? Any suggestions?

Bounty two ply and windex work well :)