We do fire and flood restoration and have never had a problem, if the humidity is right ,
Your describing oxygenation, or oxygen water.This happens when the air is heavy with damp and you introduce oxygen (ozone).If you control the damp with
dehumidifiers you should not have a problem.You can further enhance the process by keeping it dark, do not allow any ultra-violet light in.
I suspect that where the spot clean had taken place and the carpet was damp, UV light was coming in directly through a window, with regards to your friends sofa, that just sounds like colour bleed to me from the beading which can occur in the cleaning process or if wet by some other means.
Having said that, we have used Ozone with out dehums with great success
We did a famous theatrical and stage school where hundreds of costumes not to mention carpets and drapes were affected by damp. with the use of ozone we prevented any further mould damage to the costumes, this saved them untold thousands of pounds.
The physical removal as you put it is carried out in the cleaning afterwards.
In 2002 Tottenham Hotspur (spit
) had a major damp problem in one of their bars, the Captains bar in fact, and a very large bar restaurant next door, the carpet with is navy blue with the crest in it, had a film of mildew right across it, it looked quite impressive, we installed ozone machines killed the mildew and cleaned and sanitised the carpets, in time for their AGM which was taking place the following the week.