So for me, what I’ve found to be really helpful in maintaining and cleaning your glass, is using the right cleaners, as well as resin blockers like RezBlock, or weekly cleaning.
So start off. It works well to run warm to hot water (depending on the type of glass) through your piece to help knock off any loose flower residue or reclaim. Do that thoroughly with the spots you notice have the most build-up. Then drain the water and switch to a cleaner. Isopropyl alcohol and some kind of coarse salt can do the job if no cleaner is available. Preferably use a cleaning product meant for cleaning glass, such as Resinate, Formula 420 or even Grunge off.
Thoroughly shake the cleaner throughout the glass as to hit every surface area inside. Be very careful so you do not let it come out and get on you. You should also wear protective eyewear to avoid any chance of any cleaner getting in your eyes. Do so until all residue has been stricken from the glass walls and percs. Then make sure to run warm to hot water through your entire piece as to remove all traces of the cleaner. Cold water will result in any leftover residue inside to re-stick to the walls of the glass.
When it comes to maintaining the glass. It’s recommended to clean after you notice your product is no longer tasting fresh, or residue has visibly built up inside your piece. For any piece, it’s optimal to clean it at least once a week to keep from any bacteria growing in your water.
Depending on what and how much is being smoked. For water pieces, RezBlock is a good tool to use for any reclaim/resin build up on the percs. in your glass, which would normally lead to clogging.