I've been using camel-baks for years (mostly as backpacking equipment, so I tend to use them for 5 or 7 straight days without washing them......)

The cleaning kits are awesome - the hanger they made is very good. You can also make one pretty easily out of a nonpainted/non finished wire hanger. But these things definitely need to be dried out thoroughly to prevent funk (but the new ones are a lot better).

Bleach can be safe if used correctly - one small drop / half gallon is usually a safe purification amount - and flush thoroughly with water when complete as it is quite toxic (and, as mentioned above, easily bonded with petroleum based plastics). Instead of this I'd just recommend a really really really really really gentle liquid soap - like the stuff they use for babies. I'd also recommend to, in addition to the hangar, try to dry this in a place with at good ventilation and air motion.

And get one with the neoprene sleeve over the hose - they are teh roxx0r.