Hello GrassCity! First time poster and lurker as of late here. First off, sorry to the Admins if this post belongs somewhere else and you have to move it. On to the meat and potatoes; I've been smoking herb for about 17 years and through all those years I've been searching for a way to keep my bongs clean and free of that bong water odor that can creep into the flavor of your bud. A few weeks ago I had my bong soaking in a 50/50 isopropyl and water solution to loosen up some stubborn deposits. While allowing it to soak I went to the coffee maker to start a fresh pot and removed the old filter and grounds when it hit me... Coffee is excellent for eliminating odors and the used grounds are abrasive. Why use salt, sand or uncooked rice when all of these things cost money. Coffee grounds are something most of us have on hand and simply get thrown away or put into the compost heap when we're through making our coffee. I mixed a little water into the grounds to make them easier to pour into the bong and stoppered up the stem with a bit of wadded up plastic wrap giving it a good minute to two minute shake. After emptying it out and giving it a good rinse it was as sparkly and clean as the day I got it with zero residual alcohol, coffee or bong water odor. About every 3 days I have been repeating this process with one change, I haven't needed to use any alcohol again. It takes about 2 minutes to clean it with some water and coffee grounds and my bong has stayed clean and free of any odors leaving me with nothing but a nice clean full flavored hit. If this information was already available and this is a double post, sorry. I searched extensively on the web for a posting on this matter and found none. I hope someone finds this helpful - Happy toking!