Root beer and Dr. Pepper, these two flavors seem to soak into anything rubber, like o-rings & poppet valves. I haven't noticed any problem in poly beer lines that BLC or PBW can't solve, but o-rings you're talking replacement. SS? I don't want to meet that root in a dark alley!
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk