questions about a 4x2x8' growspace (mites)

well SWIM is growing in his 4x2x8' closet with sliding doors. he has a few layers of tarp velcro'd to the inside of the closet for light proofing and to create a seal for ventilation. he just set things up with 6 "purps" teens from the club and started to see slight mite damage after 2 days! (he thinks the mites came from the club!) he took all precautions including wiping walls with lysol wipes, vacuuming the carpet inside the closet and around the outside of the doors, taping plastic down over the floor. he hasnt been able to actually see any mites crawling but thinks he is maybe seeing tiny eggs under leaves. he has sprayed twice with neem solution and the problem hasnt seemed to get worse but SWIM knows from experience how TERRIBLE this situation can get. a few questions about this situation:

1. how the hell is he supposed to keep mites out of his room closet in the long run?
2. he just ordered some floramite, and will use it soon, but if the mites are dead on the plants, will he still need to worry about mites in the growspace?
3. he is considering buying a pyrethrum bomb, but will it be ok to use a pyrethrum bomb in a CLOSET?

thanks

NO to pyrethrum bomb. You may kill the plant, or make yourself sick smoking it.

Use flypaper strips.