Had my cornis for a while now and I clean with soda crystals and sanitise with iodophor, using co2 to push it through the lines and tap.
Every few brews I dismantle the posts and dip tubes and clean separately - I've never bothered with the tap though. I guess I should be disconnecting this and cleaning it separately too for a thorough job What does everybody else do with their taps?
I might be a bit OTT but I clean the pipes, disconnects, taps and poppets every keg refill.
The taps I find, collect brown sludge quite easily so I like to clean mine quite often compared to some. This usually involves stripping them down and soaking in oxyclean, rinsing then sanitising with iodophor.