A tube used for masking the scent of marijuana smoke. Consists of a card board tube from a paper towel or toilet paper roll, scented dryer sheets and something to fasten a dryer sheet over the end of the tube like a rubber band or hair band. Made by putting a sheet or two inside the tube and fastening a sheet (or 2) over one end of the tube with a rubber band. Exhale the smoke through the open end of the tube through the scented dryer sheets. Used when smoking in situations when marijuana smoke is not appropriate or accepted.
When smoking pot in your parents house use a doop tube to cover the smell. Smoking pot in a hotel room and your neighbors are threatening to call the cops if they smell it again, one should make a doop tube.