I have seen home remedies suggesting the use of baking soda to remove pet odors. Baking soda absorbs odor molecules from the air. This is why people often place an opened box of baking soda in their refrigerators to absorb food odors. Odor absorbing would be the benefit of applying baking soda. Baking soda is alkaline (base). Much of the urine odor is caused by ammonia. This ammonia is alkaline (base). So adding baking soda to a situation where ammonia is already present only increases the total alkalinity. This could potentially allow the ammonia (or ammonia and baking soda combination) to do greater damage to the dyes, removing color from the carpet.
Baking soda is also a key ingredient in carpet deodorizers such as Carpet Fresh, Love my Carpet and so forth. These do not get completely removed from the carpet by vacuuming. Repeated use of baking soda or products containing baking soda will build –up in the carpet. When cleaning time comes, this can wick to the surface creating a real mess and the need for repeated cleaning to eliminate the powder.
Baking soda absorbs odor molecules from the air. When odor molecules are removed from the air they cannot enter our nose and the smell is effectively gone.
Increase in total alkalinity can be harmful to the dyes in fabrics.
Build up of residue in carpet or fabric creating the need for repeated cleanings to remove it.
Baking soda does not digest, break down, encapsulate or neutralize the urine residue molecules past absorbing them from the air.
Also see the advantages and disadvantages of using vinegar on pet stains.