Richard
Without looking into this in any detail, all I can say is that I'm working with 100 - 130 psi. Before buying the CFR hand-tool I had an external-jet upholstery tool and this did tend to thrash the fabric ahead of the vacuum stroke. Sometimes this has benefits, but the misting action of the enclosed jet definitely controls the rinsing moisture. I'm impressed with the CFR-tool principle, although I still use enclosed, external-jets for carpets.
Regards
Pete (JS2)