i use oxyclean to clean my glass pipes...you can't save the resin this way though. just get a big bowl and boil some water on the stove. go ahead and put a few tablespoons of oxyclean in the bowl. pour the hot water in, add some more oxyclean, gently places pipe(s) in the bowl. the amount of time they have to spend in the oxyclean water is dependent on how much resin is in the pipe. sometimes i have to clean my pipes several times as well. if there are still bits of resin in the pipe, make a water solution with oxyclean and pour it into the pipe and then rinse with hot water. this always gets my pipes crystal clean with no resin anywhere on the pipes!