I use it to break in new tires. Heres my method with brand new tires: Do this outside or somewhere you don’t mind making a bit of a mess, I do all of these steps inside a cardboard box lying on its side to keep the mess to a minimum.
1) obviously glue the tires onto wheels first. Then mark the direction on inside of each wheel with an arrow pointing in the direction the wheel will spin on your car.
2) With a power drill, and AKA’s tire prep tool (or equal), and a green Scotchbrite pad, mount the wheel on the tool, switch the drill to spin according to the direction you marked on the wheel. Hold the Scotchbrite pad down on a work bench spin up the wheel and lightly scuff the tire to take the edge off the tread (or with slicks until the shine fades to more of a matte texture.
3) Take a microfiber towel, fold it in half or quarters. Spray a liberal amount of penetrating oil on it about the width of the tire.
4) Spin the tire up on the spot where you sprayed to penetrating oil. Apply moderate pressure and keep spinning the tire till it starts to smoke and continue for an additional five seconds. Sauce the tire with penetrating oil again while it’s still hot and set it aside to cool off. After the tires cool, I place them back in the bag they came in and let them stay there till I’m ready to use them, or if need be, I throw them on the car and hit the track.
5) I sauce the rears with penetrating oil every run, I only sauce the fronts twice with penetrating oil, then with sticky kicks after that for 2wd, 4wd I sauce the fronts too as needed, I use it as a tuning aid to increase or decrease steering.
Penetrating oil will make your tires swell over time if you keep using it over and over. I have found that by the time that happens with my rears, the tread is usually long gone anyway, for the 2wd fronts, not so much, the tread lasts long enough to where repeatedly saucing them with penetrating oil will soften them too much and cause you car to do strange things on the track. Most people don’t want too much bite in the front on 2wd anyway. With slicks, I’ll only use penetrating oil a few times, then I go to Purple Sticky Kicks or Green/Yellow dot FDJ sauce.

This method has been extremely effective for me and countless others, especially for indoor clay tracks.
I have literally traction rolled on dry clay, on treads with this method, tune your car accordingly, hope this helps.
Have fun!!

Check our Ryan Harris’s YouTube channel, he has a video on there for tire prep, it’s similar, and it is also extremely effective.