You have to be a survival hunter and the person your dueling has to be level 40+
Well I was messing around dueling a 40 rogue and I used rank one Wyvern Sting on him when he was almost dead before he came out of sleep i shot him and it finished the duel, next thing i know he died Wyvern Sting never went off and it killed him from the poison.
When you put your target to sleep though make sure you are able to finish the duel with one shot or this will not work i tried it over 10 times on random people and it worked on every single one that i did it correct on.
Sad part is it dont make them take durability.