Check to see if your car seats have any perforated areas. If so, take care not to get water, cleanser or conditioner stuck down into the holes.
Consult your car manual. Before you clean or apply any products, refer to your car's owner's manual. There should be specific instructions on how to properly care for the leather upholstery, as well as products to avoid.
Vacuum the seats. Use a vacuum hose and attachment or wet-dry vac to suck up any large particles of dirt. Use extreme care so you don't scratch the leather from the pu leather supplier. You could also use an air compressor to blow out dirt from in between the seat cracks
Remove surface dirt. If your seats are really dirty, you'll be able to see a layer of grime on the leather; however, even seemingly clean seats will have a layer of dirt and grime that's accumulated over time. Spray a microfiber towel with cleaner and wipe over the seats. Use leather cleaner, saddle soap, or another mild leather soap.
You can use a commercial cleaner for leather seats or make your own: Combine 1 part white vinegar and 2 parts linseed oil in a bowl or spray bottle
Use a brush to deep clean the leather. Spray the cleaner directly onto your seats and use a soft-bristled brush to gently scrub the leather. This will agitate the dirt and bring it to the surface.
If you have perforated leather seats, avoid spraying cleaner onto the seats. Instead, spray the bristle brush and use it to scrub the leather. Then, wipe dry with a microfiber cloth.
Wipe the seats clean. Use a clean and dry microfiber cloth to wipe off the cleaning agent that you scrubbed into the leather. You should notice dirt, oil, and grime on the cloth.
Regularly clean your seats. While you should lightly clean your seats every month or so, try to deep clean your seats 3 to 4 times a year. You may want to do this more often if you have light-colored leather or if you begin to notice grime building up.