As I understand it they (the “hard core” monks) don’t wear clothes and also don’t wash—so they’re “wearing” mud and dirt. I don’t know if this is still practised today. Anyway, for lay practitioners it is quite different.
(Probably the monastic community has decreased in number considerably because the pulling out of hair as part of the ordination ceremony has become somewhat unpopular… )
We may certainly find some of their practises quite silly today, but @gnlaera is right, we shouldn’t ridicule the people; and we should bear in mind that a core part of their teaching is about non-harming.