FYI, I saw this post but have never needed to use PAM either...so I was letting others who have, take your questions.
Don't know if "one quick pass" is good enough...but "drying time" is as long as it takes! (humidity varies from place to place...Florida is humid so it takes longer)
I would NOT switch back to regular substrate UNTIL you are SURE that ALL mites are gone...you won't see them in other substrate until they're so plentiful they
might kill your snakes. Other abnormalities show up better on white paper towels too...new snakes should be observed for any tinge of blood in stools, etc etc.
Housing your snakes on dry treated paper towels should not be a problem when the snake defecates (urates or stool), assuming there isn't a huge amount of
liquid...I'd recommend you clean it up (change paper) promptly if there is.
Not sure about using PAM on other substrates...(what does the can directions say? everyone only talks about using paper towels with PAM...)
Sounds like you'll need to treat your whole collection if you didn't quarantine your new snakes (w/ mites) from the others you already had. Big mistake...not fun
to have to treat entire collection, it's much easier to miss a few & keep getting re-infestations.
Yes, you need to switch the whole rack to treated paper now...good luck!