Update: 3 drops seems like it does a great job keeping the can/percs, and most of the neck clean and shiny. The only part that still gets cloudy from condensation of the vapor, is the top of the neck, and the joint that doesn't get touched by water during the draw. A quick scrubbing with a toothbrush, during the hot water rinse, gets it nice and shiny again. A very faint layer of cloudiness was forming on the inside of the can, but it was only visible if you held it to the light at the right angle. It didn't smell, or affect taste, and the bubble stacking was still great. Gave the first iso and salt shake today since Thursday. Definitely a cool/useful science-y product.
Will be using it in all pieces from now on, for it's ability to keep everything including the percs, shiny as new for sessions without any chemical cleaning.
No need to put so much that the water turns pink.