There are two different types of pet stain removers, volatile chemicals (chemicals that react with certain compounds) and enzyme products. Chemical products work by changing the chemical make up of urine. This is all great except for the fact that you’re using a chemical on your flooring or carpet and chances are you’re not going to get all the chemical out. These chemicals can remain in the dye pores and fibers of your carpets for many years or until the carpet is replaced. Enzymes work by eating the urine on the floor and then turn anaerobic and die. It seems really gross but you can't see it happening and enzymes are a part of nature unlike man made chemicals.
In my experience I have dealt with both types of concoctions and feel that enzymes do the best job. Enzymes smell better and won't harm your carpets and are more environmental and people friendly. When using either of these methods there is one truth that holds true and this is where the "sometimes they work and sometimes they don't" statement comes in. If the enzyme or chemical does not come in contact with the pet urine it will not work. If you’re pet stain problem is to the point that the wood or cement underneath the carpet has been saturated for an extended period of time it's time to call a construction crew. Your sub floors will have to be replaced and cement has to be sealed, this is the only way to get rid of cat urine odors once this much damage has been done. For some of my customers that I talk to it just seems like having flooring removed or cement sealed is too hard to swallow and there just has to be an easier and cheaper way to solve the problem. The truth is that once cat urine as seeped into a porous substance like wood or cement nothing can remove or neutralize it. When it gets damp or humid that smell will always come back and in some cases get worse over time.
For infrequent pet stains or pet accidents pet stain removers can work extremely well. These products can easily neutralize and eliminate pet stains on a carpets surface or already sealed flooring. Don't be fooled by amazing products and 100% guarantees because if they haven’t seen the problem the product is going to tackle they might be doing a good job at removing your money from your wallet and not the pet stain from your floor.