I don't know if all suppliers cartos come with rubber caps (don't like to call them condoms LoL.) If your suppliers' do, simply take scissors and cut off one of the caps on the closed end (about 1/8") to form a sleeve.
Simply slip the sleeve over the mouth end of the carto and wahla! A comfortable drip tip that keeps the juice out of your mouth and the hot end off your lips.
Simply slip the sleeve over the mouth end of the carto and wahla! A comfortable drip tip that keeps the juice out of your mouth and the hot end off your lips.