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

I've tried about 10 of these plugs ranging from standard 14mm holes to STAX 34mm plugs and options in between. Only one of my tubes, a small bubbler, has the plugs on both ends staying tight. In all other cases, at least one side of the pipe (and sometimes both) has slippage problems. You certainly can't clog both ends with most glassware and shake the salt + iso inside like crazy. Instead, you insert plugs, awkwardly place your thumbs on the plugs to create extra pressure, and then fail because the plugs are hollow and have two ends. turn diagonally again. I like it about the pipe he's working on. Good idea, I won't buy again. Maybe try a different brand.