Chris,
I never use more than a single blower - I consider the most important drying to be extractive rather than evaporative ( This is not a critisism of Mike* )
An average 10-cushion suite will take me about 3 Hrs. and the standard proceedure, after inspection, testing, set-up etc. is:
Though pre-vac with vibrating upholstery vac.
Mist-spray 2 or 3 cushions and brush in with tampico brush.
Extract first cusion useing CFR or Kleenrite hand tool.
Finish first cushion with terry towel (french-folded & turned frequently). Stack first cusion in drying area.
Pre-spray and brush another cushion, extract second cushion.
And so on, always with some cushions pre-sprayed in advance, untill it is time to move on to the carcase, which I normaly clean with a curtain tool.
The blower is normaly introduced after the first few cusions are cleaned, and is the last thing to leave the house (along with me and my wallet).
The above is a 'basic' description of proceedure, which is addapted to suit circumstances, such as required dwell-times, drying times of pre-spray etc. There are also additional proceedures, some not directly associated with removing soil, which are probably peculiar unto myself, which I may carry out.
With problem staining, eg from a 'sat-on' biro, the cusion is pre-treated and put to one side for prolonged dwell, thick wad of absorbent material on the underside,
rather than interupt the flow, then brought back into the sequence at the appropriate time.
What is most important to remember is that the most important drying takes place in the first second.
Any further extraction drying is subject to the Law of Deminishing Returns, as the liquid (and any soiling still present) is drawn into the pad, from whence it may wick back to the surface. Your aim should be to leave no more liquid than the surface fabric can comfortably hold at the end of extraction.
If a suite takes "overnight to dry- longer sometimes", it is most likely due to over-wetting the substrate.
*When this occurs even three blowers are unlikely to effect 'dry before drive-away', so even without blowers, Mikes' suites would probably be dry in a couple of hours.
John.