I use the denture cleaner tablets on my bite valves and bottle caps too, but they don't take off the biofilm. If it were dentures, you'd still have to brush them, and you still have to brush your hydration gear. Camelbak sells long flexible brushes in diameters to clean both flexible and straight drink tubes, and that's probably the cleaning appliance that gets used more than any other in my household. Then any bottle brush with a hemispherical arrangement of the bristles.

Today I filled my stainless bottle with a 10% bleach solution and let it soak for half an hour or so ... probably overkill, but I've seen what grows in there one too many times.