I normally use the60-ounce bottle of Bissell 2X Pet Stain & Odor along withBissell Pet Boost solution in aProHeat 2X Revolution Pet upright cleaner . And while I know you're out there, I'm not a member of "oh, there's a little stain from when Fido was little" club. I fall more along the lines of "it isn't practical to tear up, burn, and replace the carpet, so I'm going to use what ever I can to get biological material out of it". When I had just one dog, I rarely needed to use the carpet cleaner. When I got a puppy who didn't especially enjoy training in the winter, I became something of an aficionado of carpet cleaning products. Months later, I was happy to return the cleaner to its home in the closet, instead of having it at the ready. And then... terror. Illness struck. Was it a dead bird in the yard? Did the dog food company accidentally produce a run of prescription laxative food that wasn't labeled properly? Has karma finally caught up with me? I don't know. What I do know, is that my 30-pound dog sounded like a 300-pound man who had been on a week-long chili binge, squatting in my yard. Trouble was afoot. And when the thunder struck inside, I was in panic mode because my 2X solution and booster were enough for just one tank. My trusty Revolution laughed in the face of puppy accidents, but this was full bore liqui-poo. It came out victorious, but not without a battle. As soon as I had cleaned up, I came straight to Amazon for a restock. This 3X product was listed as a similar item, but it's NEVER in stock. With my karmic debt repaid though, it was available with or without Febreeze. Exploiting my (relatively) good fortune to the fullest, I opted for the Febreeze version and crossed my fingers in hopes of it arriving before I needed it again. As luck would have it, it arrived along with the booster just 12 hours before the next incident. This time, however, I was delighted -- yes, DE-LIGHT-ED -- to discover just how easily it came out of the carpet with the 3X formula. I didn't really expect much more than a different scent, but this works SO MUCH BETTER than the regular 2X formula when it comes to serious carpet problems. And the scent? I mean, to the extent that you can call anything about cleaning up dog poop "pleasant", it's really pleasant. It's what I would imagine a room wallpapered with fabric softener sheets would smell like. Would I want any room in the house to smell like this all of the time? Well, no. But compared to other carpet cleaning solutions I've used, it has knockedRug Doctor's "Blue Wave" scent off of its mantle. Granted, you're paying a little more and getting 12 ounces less than if you went with the 2X version. And truth be told here, the 2X version with the pet booster is totally fine for puppy accidents. But when you need all of the cleaning force you can get, you won't regret buying up to this. (But if you think fabric softener sheets are especially gross, stay away from the Febreeze version.)