Cheers for the replies gents.
@ Jim; To describe the chairs better they are a red flocked fabric, kind of a paisley effect. Pretty dirty and worn, but it's an elderly couple and they don't want to replace them. They've actually raised one of them on flower pots to make it easier to get in and out of - that's the kind of job it is.

@ Pete; I've got a fairly cheap upholstery tool that came from the States that has a pretty fine jet on it (well it mists pretty fine) and a Spitfire 4.0 (I do hard floor restoration and I'm a relative newbie with carpets - up to now no upholstery).
I was going to pretest for shrinkage and dye transfer, apply a m/s, agitate with a microfibre mitt and rinse off gently at about 100psi with Clearwater Rinse in the tank (if I can get the 4.0 that low

) - am I on the right track? @ Pete - I've got PSG - would that work better than a m/s in your opinion?
Thanks again, Chris