Before I bought my prochem machine I was thinking of hiring one, to start me off but they have a low psi pump and a small tank, ideal for car valeting but they downscale the pump so people dont over wet the carpet and shrink it etc
also its acheaper pump so they can replace it when it burns out, a day of training will be the best thing you can do, as thats what i have done and I got myself a machine which is capable of good results, later on I may go for a truck mount but for now I'm ok as I also do window cleaning this is a new venture for me, if you read my recent post on here I wrote about what chemicals I was thinking of prochem chemicals but I have now found another firm what does a sample kit for £40 to get you going.
The only thing I need now is experiance, get a machine with min of 100-125psi with at least 2 vacs suction.
otherwise you will just bring up the deep dirt to the surface and will make things worst. I think what I am saying is pretty good adice even tho i am a newbie myself.
Regards