it's good to hear that it's normal for them to drool some water, I haven't noticed any other problems so I think I'm in the clear. but if I notice any other problems I will come straight here.
I use aspen because it's cheap and I've been told that it's fine as long as they have a humidity box. last time he shed he gave me one full healthy shed in under 12 hours so I think it's fine for him. though I've considered using a forest floor substrate that I have or even mix the two (without over hydrating it). some people have said that aspen molds when it's in contact with water? I personally never noticed any mold and his water dish always spills a little lol