Hi,
I'm pretty certain PAM would kill the tarantulas and crickets along with the mites.
I also did a quick search in the inverts forum for you and came up with these threads;
Thread 1.
Thread 2.
Thread 3.
You could also possibly use the sticky leaves from a sundew plant to mop them up - just be carefull about that one though as it might be too sticky and hurt the pet. I mentioned it merely because I used to use it to get aphids off houseplants.
dr del