I'd like to think the companies that make those rental machines have innovated to the point of fool proof. I still randomly hear stories about carpets getting too wet. They definitely do the trick. I get my carpets cleaned about once every 12-15 months with no problem, but the guy knows the equipment much better than I.

As a random side note about pet hair, a couple engineers at your vacuum's company suggested spot treatments for spills and vacuuming a space five times before it's considered clean. I heard the same from one of its competitors I was in a meeting with. Just a thought.

If you go for it, be curious to hear about the results.