As well as Bissell, Hoover is another reputable brand of home carpet shampooer. The one I use looks like an upright vacuum cleaner and has rotating scrub brushes on the bottom of its head. I’ve even seen a church that kept a Hoover of this same kind to shampoo its well trodden aisle carpets, which were worn but clean. The brand name shampoos work OK but are pricey. Stores like Wal-Mart have their own generic shampoos that also work OK. Simple Green also works. Any cleaner that is not overly sudsy and does not leave a lot of residue will work. It’s a good idea to ventilate well with Simple Green as the vapors can be irritating to the eyes and respiratory tract. Household ammonia is powerful too as a spotter or in the machine, but definitely needs lots of ventilation.
I got kind of put off Hoover when the last vacuum cleaner I bought from them had a bunch of plastic knobs that all broke off within a month. They were critical to the operation of the unit. I traded it in at Costco for a Bissel vacuum cleaner as well.