Oust kills odors in the air by killing the bacteria that cause them. It really works!
The directions suggest that to kill all the airborne bacteria in a 12 x 12 foot room you should close all the doors and windows, and spray the product for ten seconds. Then leave the room until the spray settles, return, and resume normal ventilation. This seems pretty extreme, but no one here smokes, and I haven’t needed to freshen a really smelly room like a locker room, or closed area where cats have been living.
For general use in a bathroom, laundry room, near a pile of wet sneakers, etc. a quick two second shot of Oust gets rid of any nasty odors.
Interestingly, the can says that you should avoid letting this product come in contact with food utensils. This warning is not on the Lysol brand product, Neutra-Air. This might be something to consider.
We like the fragrance-free variety. There is a very slight fresh scent even so, but it is not bothersome.
Oust clears the air, and is cheaper than Neutra-Air.
Update On Aug 15, 2008: We are needing to spray around the litter box more now, we have a very old kitty. The Neuta-Air (see that review) does a better job of neutralizing this oder than the Oust.