The idea behind a odor counteractant or pairing agent is to neutralize offensive odors. I took a strong, offensive odor, ammonia, and added the counteractant to see which product seemed to neutralize the malodor the most effectively. Because animals olfactory nerves are the only way to detect odor and my dog doesnt talk, I figure the only way to measure effectiveness is to test the counteractants in exact quantities added to the malodor, ammonia, in an equal amount and smell to determine which one neutralized the odor. This came about when I tried neutralizing urine odor in an extreme urine job by cleaning the front and back of a year old nylon and was disappointed with the results of the quatalot and not overly enthused by odorcide. I am running out of odorcide and need to buy another case, but at $100 a gallon, I wanted to know if there was an equally effective odor counteractant at a better price. When I returned to the office, I added ammonia in different containers then added the same amount of various counteractants to see which one could neutralize the strong odor the best. It was that or pee in a cup myself as most dogs dont like you following them around with a cup! It may not be the most scientific test, but it did pique my interest. I would be interested in any ones personal side by side comparisons other than a single product applied in a job. I have had very good sucess with osr, odorcide and dd12 but this job was less than stellar. Guess we all have them but it made me take a little harder look at odor counteractants since I need to place an order soon.