This is a great product. Paired with a CO2 tanks and the correct fittings, this nozzle lets me carbonate literally any liquid I want. Mine arrived with the internal barb fitting loose, and I wasn’t sure how tight it needed to be (will I damage a gasket if I screw too tight?), but finger tight seems to have worked.
It should be common sense, but I would recommend NOT shaking your bottle while connected to the larger system. The nozzle allows fluids to move in both directions, which means any liquid in the bottle can migrate into your line, creating mold. I would recommend getting the bottle under pressure, shaking to help the CO2 get into solution, and pressurizing a second time before resting.