I have never used that stuff as a dunk, but in my experience if you are using a foliar product for a dunk instead, you want to dilute it WAY down!!! Like, take the given dilution and then dilute it by 4-5x again!

Honestly unless you are trying to be all organic and shit, get your butt to home dePOT and get the Raid pyrethrin-only bug bombs, blue and yellow package, like $7 for 3 of them. No other chemicals, just pyrethrin. Works great, gets out of the air in 4 hours.