This from the brilliant novelist Melissa Miller:
I thought of an idea for the How To Be An Adult site ... I have carpets in our bedrooms and they have fallen prey to both the kids and dogs in the urine department. I hate the stuff that they sell for such odors and don't think they're good for my family or pets to breathe, or for the environment. What I found works like a charm is to sop up the wetness, clean the area with a good cleanser (I use the new green series by Clorox or something by Seventh Gen.) and let it dry ... then the piece de resistance is plain old baking soda. I sprinkle it over the stinky spot and brush it deep into the fibers with a hand broom. Let it sit for the day and then vacuum it up! This also works for every day kinds of pet odors in carpets ... vacuum the carpet, shake the soda all over it, brush it into the fibres, let it set and then vacuum it up!
Nerissa says: the wonders of baking soda! We keep countless boxes of it in our pantry and in all our bathrooms. Combined with vinegar, it is a powerful, earth-friendly all purpose cleaner.