Hi Les,
It's not as specialised as some may make out, that said if you want to be efficient, it does help if you have either a dedicated solvent machine preferably with a heater or a HWE machine with a solvent kit, like I do, I use Ashbys' own label mineral solvents and have never had a problem, obviously you change you spotting chems accordingly, but the principals are exactly the same as fabric upholstery, ie, pretest, removing loose soiling prespot and clean, ideal temp for solvent is around 50 to 60 degrees. All that said you can still do the job by hand with a tampico brush and terry cloths but it is hard work.
Regards
Ralph