I would be VERY careful ripping open the surface of any kart track and putting any Soap, Calcium, or even just to much water for that matter in it, especially Calcium and mix it in, that may work for the chili bowl however Remember they have every piece of equipment needed and it's all new, plus YEARS of trial and error with volumes and and timing, you could try this and screw yourself royally, it's most important to understand what material your dealing with, but what would be least expensive and make the biggest difference for now is simply apply most likely 10 times as much water on it as you are now, then the final load mix in the white soap, any track can be prepped all from the surface and hold you just need to learn how to work it with proper volumes
and timing of it, especially if you use calcium or mag flakes to the surface with proper moisture.