So I just hit 60 and I decided to do the 3rd daredevil fair challenge for exp and to finish off some combo achievements because why not. I learned that by using toxic spray with my sorceress' cool down reduction buffs i can spam it for easy combos. I've hit 300-500 numerous times yet no pop. I'm pretty sure I did this on my assassin so I don't think its because its the daredevil fair.