Phoebe: What good is it being a witch if I can't just twitch my nose and make the laundry fold itself?
Cole: Uh, which witch can do that?
This is a reference to the series Bewitched. The lead character Samantha, who was a witch herself didn't rely on potions or incantations, but twitched her nose to work her magic. Her daughter Tabitha also moved her nose (with her finger) to perform magic much more efficiently than Phoebe or her sisters.