Review on Hemper Tech Universal Cleaning Plugs+Caps for Glass Water Pipes/Rigs - Ideal for Cleaning, Storage, and Odor Prevention by Justin Miller

I've used them on the 2 pieces I have, both 14mm swivels with the same size narrow mouths. I've had no problems with them, love them, I used to use a paper towel bundle and it soaked up about half my iso. I don't shake them too vigorously, no need, a gentle rolling and a pinch of coarse salt if needed will bring the item to a pristine shine. I'll see how they hold up, but so far I'm very happy. I haven't held items upside down for long periods of time, but I do hold them sideways and shake them vigorously for about 2 minutes at a time. I used a small one on an activated charcoal filter, that also worked with no problems.