I can't speak for cleaning a MM, but here's how I'd recommend cleaning one of our Old Dominion cob pipes. The outside of the bamboo stem can be cleaned with unscented isopropyl alcohol (70%). The alcohol won't hurt the stem and dries quickly and leaves no residual odor. Like the original bamboo stem cob pipes, we do not glue the stems into the cob. The stems are carefully tapered so that they can be inserted into the stem hole and twisted to make a tight fit. Therefore, they can be removed for occasional cleaning if necessary. I just would not recommend removing the stem on a routine basis as overtime you could cause the stem hole to widen, thus creating a loose fit. A piece of wire, standard pipe cleaner, or a long 1/8" drill bit can be used to insert inside of the stem and be twisted around to remove any obstructions or build-up. Care should be taken in cleaning the inside of the bowl. My recommended method would be to take a clean, dry twisted paper towel and twist around inside the bowl to remove any loose cake if desired.