Since I do full restoration and restaining I don’t really sweat it to much. I always assume I’m gonna find a dumpster fire underneath a heavily caked rim that needs to be repaired. Having said that, out of the hundreds of pipes I’ve used carbon off on, I’ve only had two or three that had to have the rims restained. I’m not sure if it was the carbon off or they were just knackered under the carbon already, it’s nearly impossible to say.
Since different companies used a myriad of different stains it’s difficult to say how they are affected by different chemicals and processes.
I would say if you are unsure or don’t have the means to fix a stain boo boo then don’t use it. Maybe get a can and try it on some cheaper pipes so you can get a feel for how it works and what it does to a pipe.
