If you want to strech out how many applications you can get from a bottle just spread it out with a small sponge rather than covering every inch with direct sprar.

From the Carpro website "2.-You can cover the surface with Iron X by spraying it everywhere but that can be wasteful. I recommend that you spray as needed and spread it with a small sponge or applicator to cover the entire surface. You may also consider using an atomizer type spray bottle or HVLP gun. In any case evenly cover the surfaces you wish to decontaminate. The product is strong so you don’t have to be wasteful. Just make sure it contacts the entire surface."