seta ui_iscensored "0"
seta g_dismember 100
//that's mp, at least dismembent works always
seta g_dismemberment 3
//that's for sp i guess
also there's this cvar i have it at 99, I don't know if it's needed at all
Also dismember doesn't work on some os if the language is not English (USA) for some (idiotic) reason. It can be fixed by changing the language in the system properties. But you would have to reinstall the game with this language settings.