I use just vinegar and water and it seems fine although my carpets aren't real dirty. I wouldn't use any chemicals either.

I have the same machine and use plain old white vinegar each time. Just fill the "shampoo" tank with straight vinegar as you would shampoo. I was told and have noticed that the carpet stays cleaner longer since I stopped useing shampoo.

I've used natural, orange based cleaners like TKO to freshen the carpets. A bonus is that the house smells wonderful after.

...Pam

What if your area rug made of wool is dirty? Will the vinegar clean it?

The good form of carpet cleaning is always prevention. Taking proper care and maintaining your carpet clean will save you money from having to buy expensive cleaning products. Never rub rashly and carelessly at a carpet stain, this may only cause it to smear and become permanent. Also, doing this will weaken the fiber causing your carpet to wear out quicker.

SharperClean is right about prevention being the best alternative. Do you vacuum at least weekly? Lay down matts by doors to catch drips,dust,leaves,etc. Shake the matts outdoors weekly. Then you won't have to clean so often. I applaud you for not using chemicals around children.