that is an unfair and stereotyping comment. care to share the names of these brazilian fighters that we might know that we can prove are dirty as you claim they are? maybe from your limited experience training under brazilian in your BJJ gym, they happen to be dirty in your opinion. but if you trained any other martial art with any other majority race i guarantee you would eventually see the same dirty fighters anywhere you go, no matter what country they are from.
from my experience i have met more dirty/sore losers that happen to be white/black/asian than brazilians, in fact. not all brazilians are sore losers just because you happen to train with sore losers at your BJJ gym. maybe your gym is just full of sore losers. that sucks.