Club Soda for Carpet Stains

I recently had my carpets professionally cleaned and I asked what is the best thing to use to clean spots without leaving a residue that actually attracts more dirt (such as Resolve and Oxiclean). He told me the best thing to use was plain old club soda. He said to pour it on let it sit a few minutes and then use a shop vac or wet dry vac of some sort to suck up the excess liquid. He said for most stains you shouldn't even have to rub at all. He said this will work on pet stains also.