i went thru the EXACT same thing, my BP wanted out of the tank to bad i caught him a few times in between the cover or the tank the the plexi glass cover i have under it.

They were all over the place, a few on my BP but not many and they were mostly crawling on her, not sucked in to her like regular mites do. Some where black and some of them where whitish. I too got caught in this problem without PAM at hand, and when i ordered some the expected delivery was like 12 days!

Anyways what i did was transfer her to my old setup 10gallon tank i had in the mean time, and lined that with paper towels and soaked her in a bath for a few minutes, then spray down with reptile relief. Like you i never saw a mite on the paper towels after doing this. Meanwhile back in the old setup i started checking everything, and of course, this big piece of wood decor i had was INFESTED with mites. They where in all the nooks a crannies. Since this is my THIRD incident with wood mites on wood decor/bark,i decided to just dispose of the wood decor. I notice that the dark wood decors as opposed to the light more flaky ones are the problem. I still have a branch decor which is the lighter white wood ones, and that i placed in boiling water. Pam finally arrived, cleaned the tank with chlorexedine, pam'd it up, and havent had a problem since.