Has anyone done this to wrinkles in seats?

I am not about to do this myself but this guy seems to show it can be done.
Can it be done to the creases in the bolsters?

How To Remove Wrinkles & Improve Fit in a Custom Leather Seat Upholstery Install - LeatherSeats.com - YouTube

Practice thoroughly on a seat from the junk yard first.

I also heard from Westcoast Customs that using a bunch of hot water soaked towels laid over the seats will tighten up the leather.

A steam machine and ice packs have always helped me tighten up leather seats. I like to clean the seat first, then I proceed to warm specific areas until they get quite warm, and then remove the steam and lightly press the ice pack onto the steamed/warmed area. This procedure has kept my 188k mile drivers` seat in pretty tight condition.