Scott,
If she has cleaned it herself with a vax & 1001 she has no doubt left loads of residue within the carpet.
Firstly I would simply hot extract using a sour rinse and
NOTHING else.You may find that this is all you need to clean it.
If after that, it is still soiled then a bonnet clean or light HWE using an MS solution ( No2) with usually suffice.
You should never use a browning solution if the carpet doesn't show signs of needing it.
As for melting points Access is getting polyprop mixed up with acrylic as Doug has pointed out.Polyprop can indeed leave scour marks when furniture has been dragged across it but I never know it to melt in a clean.
Good Luck