Once it kicks, just leave the CO2 pressure in the keg and it will be fine for months. Not much is going to grow in there with just a CO2 environment - I've left them for months and never seen any sign of something growing in any of my kegs. Even after that long a pbw soak cleans them up just fine, although I recently built a keg cleaning rig that makes it go much faster. I break mine down completely each time but lots of people don't with no problems.
I accidently left one sitting in my basement with about a half gallon of oatmeal stout in the bottom, from the first weekend in October until February 16th.
Inside, it looked like I had just left it down there, the other day.
Nothing funky, at all.