I have a cleaning company and am about to start doing carpet cleaning, Im trying to find a inexpensive solution.. that works well..
Vinegar or Ammonia?

Ammonia will destroy carpet. Vinegar will do nothing to clean it. This is not about the best cheap cleaning product, it is about professional equipment. If you can’t drop $1500 on an entry level dual motor extractor, you have no business doing carpet, because you aren’t really cleaning it.