As you know (maybe) I have leaf chams with substrate so I probably shouldn't be commenting here but I would think that once an week is a good habit regardless of them being meesy or not. You'll have crix feces. which other crix may consume. as well as your cham's feces. So for good sanitation I would change them at least once a week - but then again I am pretty obsessive 
lele
>>this is a pic of my veiled's enclosure ... the bottom WAS pine chips at the time, but now it is all paper towels!
>>Just curiuous, how often do the paper towels need to be chamged? i have been doing it every week, but if it isnt messy, is once every 2 weeks ok?
>>
>>-----
>>Jason, Ichiro, Mika & Toki
>>1.0 veiled chameleon
>>0.2 dwarf panther chameleons
>>jsinger_jimt@hotmail.com