i drink kind of often so i decided to actually buy a breathalizer. i haven't tried it with mustard packets yet (lmao), but the directions say to wait 20 minutes after eating, drinking or smoking and i heard that's what the cops do also... i got the alcohawk pro from breathalyzer.net. seems to work pretty well so far... i'll try some mustard packets next time i drink and let you know what happens!