I have been very intrigued by this product for a variety of reasons.  I prefer using milder chemicals, if effective when cleaning the interior of a car.  This is especially the case with leather seats.  Gyeon Leather Care is a product for leather and is advertised as mild enough to not remove its companion product Gyeon Leather Coat.  How strong of cleaner could this product possibly be? I will be testing this product on seats, that upon first glance would appear to need some diluted mix of an all-purpose cleaner to remove much of the soiling.

The seats I am working on are perforated leather.  The seats have not been cleaned in over two years.  The vehicle is driven daily by a driver who is very physically active.  This leather cleaner was up for quite a challenge.

I would work in sections that would expand by a range from dimensions of my hand to that of your standard size notebook paper (8 1/2 x 11).

I started with 4 to 7 sprays in the area, let it dwell for 20 to 40 seconds, scrub for about 20 to 40 seconds, then wipe off with a microfiber towel. When I used the brush to scrub the product, it was straight line motions back and forth and then side to side.  The pressure applied with the brush was light to medium.  Medium pressure for me would be applying downward pressure while consciously trying not to make a muscle.

I immediately was very impressed with the cleaning action of this product.

Between 70 to 95 percent of the soiling had been removed via the first pass.  You can see above the significant difference above between the spot I was working on and what had yet to be touched.  It took usually two passes at most to restore a section to good condition.

Things of Note

With good products, a little often goes a long way.  The same can be said here.  As I continued working I dialed my technique down to consistently spraying 4 times max and with a working area expanded to 8 1/2 by 11.  I recommend the same approach for even highly soiled seats.

I also rinsed off my brush at about the halfway mark of the second seat.  I noticed the brush was taking in more of the dirt than the microfiber towel.  The scrubbing action was noticeably better immediately after rinsing off the brush.  Depending on the level of soiling, a periodic rinse or new brush may be something you would want to consider.

Below are the results.