Seems product worked as stated. Our problem has been reduced tremendous. I found that you cannot skip any applications without a pest return. I treat every drain every three days. I gave it three stars because it does not eliminate the problem 100%, but does show a dramatic improvement
Based on all accessible info, this product appears to be better quality than most in that it has 5 strains of bacillus microorganisms and contains over 550 billion cells per gallon which are needed to reduce the bacteria laden bio film and digest the organic waste that is in our drains that flies feed and reproduce in. I do not know how this product compares with DF 5000 Drain Gel.
Had drain fly issue in two bathrooms, in both sinks and shower drains. Prior to using, I cleaned drains as best as possible (baking soda and vinegar plus snaking tool). Used Drain Gel as directed or six consecutive days (four ounce applications overnight, a full twelve hours each treatment). After first couple days, a few flies still emerged after rinsing/using the drains. Flies did not/could not emerge while the drains were coated with Drain Gel. Frustrating couple of days, but patience paid off- no more flies after the sixth treatment day, and no flies since. Would definitely use again but hope I never have to use again. Also, the blue color makes it easy to verify that the pipes are properly coated, and the smell is easily tolerable and not unpleasant at all.