A cheap way to kill lice is bury the infected clothes under small stones as shown in the photo below.
After a few hours all the lice is dead, and your clothes are essentially disinfected. No more itching down there, and having lice eggs hatched all over one’s pubic hairs.
Eritrean soldiers used this system for years during their civil war when soap was scarce.
One way to kill lice, which were rife among soldiers, was to bury clothes under small stones, a war veteran told me.
Source: Eritrea celebrates 25 years of independence after war with Ethiopia – BBC News
How about the ones that have clinched unto the body especially the hairs, armpit and other places?
It’s better to prevent it at all cost than curing it.