In my opinion, red stains -and some other colored stains as well- are not a "one answer fits all"
How do you know what was used on the stain to "try to clean it" by the home owner or how do you know it wasn't there when the last carpet cleaner "cleaned" it. (Which means it my very well be a set stain that you will not get out!!)
Same thing with candle spills-in the other thread where "danielc" talks about how he came up with warming up gum before removal. (Old trick by the way)
Shorty asked about the wax. If you are using a steamer and or iron to warm up the wax, how do you know you are going to be able to remove the color that's left behind?? You could be setting the stain right there and then!
I have had success with red relief, red1, red vanish. Then again, all these products and procedures fail from time to time on what seem to be an identical problem to what I just got rid of the day before.
So if the home owner can't give you the precise history of what happened, how long it was there, who tried to clean it and with what product- I just tell them: we will be getting paid for the attempt and not the result.
Zee