At least that's how we tried to explain the process to the extremely intoxicated teenager who arrived in the ER covered in vomit over the weekend. Poking him with the straw, I asked him to blow out like he was blowing out a candle.
Eyes still mostly closed, head perked up a little, he affixed his lips to the straw, but rather than blowing out, he started sucking.
Said the medic, "Not that kind of blow," as he continued to go to town.
I half expected the breathalyzer's LED screen to light up a smiley face as it got more action that night than any of the rest of us.