Most people dont understand how octane booster works. Or octane for that matter. Octane is the resistance to detonation. If you dont have high compression, forced induction, or timing advance out the **** then there is no need for it. It wont do you any good.
But i have first hand see this homemade octane booster work. A friend of mine tried it in his 03 bolt on cobra and i tried it in my car (and advanced the timing to take advantage of it)

-1 Gallon Xylene (Highly explosive fuel, also used as a sort of paint thinner, has an extremely high octane rating, can be found at hardware stores)
-1 bottle 90% Rubbing alcohol (Isopropyl, Basically a form of liquid propane, can be found at walmart of wherever)
-1 bottle Hydrogen Peroxide (It separates under combustion into hydrogen and pure oxygen, Hydrogen is flammable and oxygen is an oxidizer, which helps with combustion.)
-1 cup Mineral Oil (Effectively lubricates and protects engine components)

That mixture is the only thing i've ever tried that actually worked. Store bought boosters are all crap. They don't do anything.

 

yeah i changed my timing.with a mac timing adjuster so i run 89 octane