I have a lot more experience than I wish I had with the dreaded funk.

I always rinse with plain water, only on rare occasions will I add a few drops of bleach to the rinse water or hot water with denture cleaner tablets. A few times I've used a long bristle brush (available in a hydration bladder cleaning kit) to scrub the tube out if it's looking suspiciously cloudy.

As for drying, first I drain the tube and try to shake out most of the water. Then I use a paper towel to sponge off as much of the inside that I can reach. Some of my hydration bladders have a big opening that I can stick my whole arm down - those I dry completely with paper towels. Others have a small filler cap - what I do in that case is stick some paper towels just inside the filler neck and use it to sop up little trickles of water as much as I can.

As long as I rinse and dry the bladders within 12 hours of using them, I rarely have a problem. Forgetting to do this, or storing a damp bladder, or leaving a bladder half-full forgotten in a backpack for a week (oh, I've done it!) usually results in the Black Plague. Note: I only use water in my hydration packs.