Tablets are biodegradable, chlorine-free, all-natural, and environmentally safe. Just pop in a tablet with water, sit for half an hour, and then wash clean. They're good for use on stainless steel bottles, mugs, hydration reservoirs, coolers, dishes, and hard-to-clean plastic containers and bottles.
Promising review: "In all fairness, I first heard of this product while watching Shark Tank, and their pitch was impressive so I gave the underdog a try. Now, I'm on my fourth re-order. My whole family drinks out of various name brand bottles, coffee mugs, etc. The fact is, they are rarely cleaned because they are a part of our daily lives and they are a pain in the ar$e to clean, because of the inconvenience that they are not dishwasher-safe, or don't fit. The answer is these tablets. They work and they're simple to use." —K.R.
Get them from Amazon for $8/12, or $19.97/36.