The dip sounds right. She will probably have you bring him back in 2 weeks after the dip to scrape again - and if they aren't gone, he'll get another dip. Keep him dry, dont bathe him or get him wet after he's been dipped. The dip will continue to fight the bugs in the pores and on the skin. I dont know what she means by caught it in time, I'm guessing she meant before it got worse (although she probably should have checked when you brought him in last week).
You'd have to fix him because hormones could contribute to not being able to get the mites under control. If you're not planning to fix him yet then wait to see if the treatment works first (ie if you were planning to wait a while before getting him fixed). Did you get any antibitotics? The mites might cause a secondary bacterial infections, so the antibiotics would help.