^ Just remember BP's usually stay hidden 90% of the time, but most people catch them out in the evenings. A hiding BP is a happy BP!

For the towel, sometimes I use one for my crestie's cage and as long as you change them out and don't keep them soaking wet for days (mine usually dry out in 2 days though, not enough time for mold to grow anyway) then I wouldn't worry about mold issues. If the towel was working the best for you I would continue to do that and just monitor for mold. Prolonged mold inside the tank is what I would be worried about.