I keep pressure on mine too. Mine are never empty though. I have worked out a good system to keep keg cleaning, and kegging easy.
I don't usually have all my kegs full of beers. So I usually have at least one filled with PBW.
So when I empty a keg I rinse it and then use a jumper line to just push PBW into the one that needs to be cleaned.
Any cornies that have already been through a pbw soak and a rinse get at least a gallon+or - of star san and put under pressure, vented, and shook up.
So on kegging day I just shake my cornie, push the star san to another corny. Dip tube and poppet get sanitized too. Plus most of the O2 has already been purge through all of this. I spend more time getting my racking cane together and properly snaitized.
I swear a jumper line is a home brewers best friend. I'm not sure how I managed to live with out it?

