"So, what do they do?"
"You stick 'em on your finger and brush your teeth with them."
"Why would you want to do that?"
"In case you're suddenly really really really really really worried that you really really really really need to brush your teeth."
"And there's no toothbrush or toothpaste around."
"And you're waiting to cross the street."
"Uh hu-- wait, what"
"So, would you use this product if you were waiting to cross the street and you suddenly had this fanatical compulsion to brush your teeth?"
"Er, probably not."
"Would you use this product if you didn't want to carry a toothbrush and toothpaste around with you and spit in public sinks, which is icky gross?"
"Probably not, though I agree with you on the public sink thing."
"Would you use this product if we made a commercial for it featuring Beautiful People dancing around like morons with these things on their finger?"