I've attached a hose to an old cheap throwaway water bottle (16 oz) using a barb. The hose gets pushed into the faucet end and I manually depress the quick-disconnect end. It cost <$1 for hose and ~$1 for the double barb. Then I just put a hole in the bottle cap and pushed my barb through from the inside. The hose attached to the barb on the outside.
When a keg kicks, my process is as follows:
-Drain beer from line
-Flush line with full water bottle
-Fill line with PBW (~2 oz)
-Walk away for 10 minutes to 2 days
-Drain line
-Flush line with full water bottle
-Fill line with Starsan
-Walk away for 10 minutes to 2 days
-Drain line
At this point it's ready for a new keg. The physical part of the process is about 5 minutes of work, but you have the wait time while the cleaner and starsan are in the line. I've looked into a pressurized sprayer option and even considered the keg route. I've just found that my system is so easy and low tech that I like it
This is just a random picture but mine looks VERY similar: