Damn the BORG!!! Sorry to hear you got infected. One method I have heard of is to get a 1 gallon pump/wand sprayer from the hardware store. Use one teaspoon, not a TABLESPOON! but a teaspoon of Ivory dish soap. Mix it with 1 gallon of clean water. If you can, take the pants out side, or use your shower to really spray them down. Afterwards you can rinse them the same way with just pure water.
This will only kill the live mites, not the eggs, so you want to follow up with predators, or another method to kill the eggs.

Hope this helps.