Stain magic or any oxidizer for a set in stain is best serve with lots of dwell time. The magic happens usually across a few hours. Your best bet.. (and charge accordingly) is to spray liberally the area that is affected. then cover with seran wrap or plastic sheeting and have the customer check on it after about 4 hours or overnight if possible. The hydrogen peroxide will neutralize as will the amonia used to boost it. But its always a good idea to return to rinse the area just to be sure.
Heat is for those times when you feel inpatient but you also at a much higher risk.
Could you or should you are two different things. Could you? Yes. Should You? No. You can open the drapes and let the sunlight in which will help as well as using a DCI Light with the chemical activation Light.
Now if you've been doing this forever and a day and aren't afraid to pull color and have a dye kit and or know how to patch and aren't afraid the home owner won't demand you replace the carpet you just ruined then sure go ahead and put an iron to it. shiteatinggrin
Yes if your going to do it Steam it, less of a chance to pull color. I was responding to the title of the thread "heat transfer" and missed the steam part.
Still not the best Idea for someone new or hell even someone that has been doing it a long time. Risk far outweighs whatever rewards it might offer.