This assumes there is a spare keg. But, yes, that's what I did before. Now my kegs stay full of beer, not PBW.Isn't it easier to just throw some pbw and hot water into a keg and use 10c worth of co2 to push it through the system?
Step 1, add pbw and hot water to a keg, say a couple of litres per tap.
Step 2, add co2 quick disconnect to keg for a sec or two, then remove.
Step 3. connect tap, and allow some pbw mix to flow, close of tap.
Step 3b. repeat for other taps.
Step 4. leave until next day, lines and taps full of pbw mix
Step 5. next day, open tap and drain remaining pwb solution, swapping between all taps.
Step 6. Refill keg with clean hot water and run through all taps
Step 7. pour beer and enjoy