It got to it.
It's really not a difficult task; takes about an hour of punctuated attention. I have six hand pulls, and consequently six lines, that service eight casks on the stillage behind the bar. The beer line cleaning product is some pink stuff from Shepard Bros. that mixes easily in a bucket of water. Disconnect all the lines, drop them in the bucket, and pull through each engine until the liquid dispensing into the little metal pail starts to appear a wee bit pink. Let sit for 15 minutes. Pull another cylinder through. Let sit for five. Pull another through. Let sit for five more. Then clean out the bucket, fill with cold water, and repeat the process until the liquid coming out of the neck is clear and non-slimy.
This is then a great time to rearrange the ale lineup, hopefully in some rational sort order such as by ABV or style. The rules of whimsy also sometimes apply, and it's fun to keep the barkeep on his toes, which is often myself. It also confuses the punters and makes them read the pump clips.
Once the lines are all hooked up, then each and every beer has to be sampled. 'Nuff said.
Cleaning the six keg lines is much more difficult, as it entails dealing with a pressured corny keg full of cleanser and lots of spidery gas and beer lines all tangled up in the cooler under the back bar.