I've seen some of the more extreme porn (scat, vomit, blood, etc.). It was gross, but I wasn't watching it to get turned on. I was watching it out of curiosity or for shock value. If I am watching something to get turned on, it turns me off if there is any type of unhygienic practice, such as ass to mouth or a guy inserting his penis that was just in a girl's ass into the mouth or vagina. Spitting and choking are a turn off as well.