The secret to these cleaning sponges is the magnetic components that allow the user to manipulate the sponges while they are inside the pipe. The kit comes with three duck-shaped sponges and a single magnetic handle. All three sponges are double-sided, so you'll never have worry about insufficient cleaning potential. Once you've placed one of the sponges into your piece, place the handle near the surface of the glass so that the double-strength magnets within the sponge and handle connect through the glass.
These scrubbers are also completely washable, so you can reuse them many, many times. Since the magnets are polarized on the axis that runs perpendicular to the surface of the glass, you can flip over the sponge within the piece by flipping the magnet handle while keeping it flush against the glass. This reverses the polarity so the sponge magnet also has to flip. Now you can return your glass water pipes to the pristine condition they were in when you bought them.