I'm interested in thoughts here too. I've not done this as it seems somewhat high in the liability department. I have mentioned to several customers that getting some dye and using a q-tip on their otherwise permanent stain would help them.
I have one customer who had the white carpeting in her master bedroom dyed a deep maroon. The rest of the house is off-white. Apparently, the dye in the bedroom didn't "set" or fully dry in the amount of time it was supposed to, and she and her husband subsequently tracked maroon footprints all through the traffic lanes on her 2nd floor and down the carpeted stairs as well. It looks quite bad, and what surprises me is that they have never replaced the carpeted areas that became tracked up with dye. I think they expect me to "clean it away" over time, but that is not happening. Also I don't know why they didn't pursue a case in court against the company that did the dye job.
