This is my fav part of those keg washers. A little bit of water and PBW. I'll clean 5 or so kegs in one cycle.
This is also why I developed a CIP for my three conicals. I was hemorrhaging PBW. Now a couple of gallons of water and PBW along with 20-30 mins cycle gets it done. Rinse, sanitize and I'm good to go. It used to take 15gals of water, enough PBW, and an overnight soak. Then, rinse sanitize the next day... ugh.