I got a sample of Klean-Wall free from his website at apchemical.com and I purchased some Mister Plumber from some Dollar Store down the street. The Fake Drano contains: water, sodium hypochlorite, sodium hydroxide and surfactants. The Klean-Wall contains: magic.
Both sections look equally as bad. The directions on the Klean-Wall said 3-5 minutes so I let both chemicals stay on 5 minutes.
The Klean-Wall after 5 minutes did a lot better job (first picture). But the Fake Drano did a pretty good job.
I reapplied the Fake Drano and let it sit for 30 minutes. It turned out a lot better but not as good as the Klean-Wall. But for the price of the Fake Drano maybe you should try Fake Drano over Klean-Wall?