Anyone have experience with leather dye for their seats?

[hydro 481]

I have black marks on my white seats that will not come off at all. I've tried many different things but unfortunately the marks seem to be permanent. I found this website Seat Doctors that sells a Tesla leather dye kit for all color seats, including the ultra white. Anyone have any experience with this or similar products?

Here's the link to the product: Tesla Leather Dye — Seat Doctors