Octane boosting will help only by controlling any pre-ignition (ie; "pinging") problems. If you don't have any "pinging" then octane booster won't help. Do you have a lot of miles?
There isn't any regulatory guidance on octane boosters, so they can "test" their product how they want. For example some boast a 2% increase in octane...but that is only 2% over what you've got in there. eg; You buy gas with an octane of 70, that booster would bring it up to 71.4 (70 x 2%)...
If you do have pinging and the booster does help, you probably have some "build -up" in the compression chamber (I'm assuming youve done the tune-ups, good air filters, etc..) that's decreased the compression chamber size thus causing the temperature to rise just enough to cause your pre-ignition...