My story is from NJ. And was many years ago. But, the buyer had to go to court. Anyway, ever vehicle I have sold was with a paper signed "as is, where is".
It is not much money to try if he has already given up on the car, what does he have to lose. I have not used this product, but I have used the same brand power steering fix fluid. I had a very noisy power steering pump on another car and it quieted it down and has been working good for a year now.
This stuff does work, up to a point. My transmission was slipping bad and it helped a lot. Then it got worse, so poured 4-5 bottles of it in. But be sure to remove adequate amount of tranny fluid to not overfill it as this would burn up the tranny. My tranny ran for over an extra year with this before I got one from a wrecked car. And this was a pretty stout musclecar with 305 ft-lb of torque that was driven pretty hard.