i must concur with joe about how cool venom splasher and poison react is...
funny thing is, i once had a sin in my previous server, used poison react with him, and i found that although 300% counter on a poison attack is nice, but for PVM multiple attack blocks are nicer...
i don't WOE here, but i bet venom dust could really mess with the opponent if used correctly... i once messed (as a sin) with an LK going berserk in front of an emp by venom-dusting him, waiting a few secs, and then started crit-locking him with 60 luk and a 3crit jur...
and although in my old server the WOE is not that crowded - too many castles open, too few players; i think venom dust could be used to help crowd control and clog up choke points...