Just a rag & motor spray. Jack will build up on the tires where Paragon does not. That's why you see gunk build up on the front tire where you did not sauce.... it returns to the tire as you run. We call it "Jack the Slipper". The stuff works if you know how to deal with it. You get your fingers black by the end of the day, hate that part. Another trick I use is front to back weight bias. I really like a 42/58% bias. Weigh the entire car and then get a equal height block as the scale, place the rear axle on the scale with the front on the block. Divide the two numbers to come up with the ratio. With Jack, if you slip the front tires too much (not enough weight) the Jack will build up, usually quicker. If the front tires have very little slip angle, they build up less. It's a balancing act between CA, D/R & weight bias.
Have fun!
Brian