Putting that stuff on your tires will not be a remote equal to slicks. I tried that stuff before on street tires and it made a very marginal difference, if at all. Street tires are generally just too hard.
actually I used it wednesday at the track. My first run I didn't at all and traction was non existant. So for the next run I sprayed the tires down twice letting them dry inbetween coats. Then I did a small burn out before I staged. When I launched the tires spun in first but I quickly shifted to 2nd and they hooked really good. SO good in fact that my clutch couldn't hold and started slipping really badly . From that experience I might use it again but I will probably just step up to slicks and see what happens. Your right about it being expensive, I pain $35 for a gallon at the local speed shop! But I figured if it helped cut back my times it was worth it. Plus the gallon should last me quite a while, hopfully all season.