PSB... Pre Spray Gold, Just to be safe. UPR (Ultrapac Renovate) is great on sooty carpets, but like PB (Power Burst), it has a very high Ph.
As you are Acid Rinsing, it wouldn't be too much of a problem if the state of the rug warranted the use of high PH chemicals... But Go easy on the pre spray, do not over wet and agitate well. Plenty of dry passing too and utilise your air blower if you have one.
All the best fella, I'm sure you'll wonder what all the fuss was about, but not all of us like to see people make mistakes...
