I prefer using a glass steamroller with bowl, copper gauze in barrel, then get some foil put crack on foil, wrap foil around bowl turn upside down, put flame to the foil and keeping a finger over rush hole, melt the crack for milliseconds then put flame on the foil and whoosh loads of pure crack smoke and no air, as its airtight pure crack, better than direct flame on crack and smoked like a traditional (tobacco).pipe, just pure crack smoke better bellringers, also once all solid cracks gone you can put the used foil rolled up in the bowl making sure resin is on the outside and get a good blast, and then the gauze in the barrel, i use copper gauze not chemically coated steel. And push it up and down barrel then put in bowel for a great resin hit, i have attached photos to help