If it's leather The fine folks at CC seats told me to liberally apply a good quality leather treatment, in my case HD's Leather Paste, at let it sit in the sun for about a half hour so that the oils from the paste absorb into the leather then wipe and excess off.
Corbin also sells a product which I bought along with the seats but when it is gone I'll just use a common leather preservative product. Montana Pitch Blend is an excellent product.
I am also curious about this question. Would kiwi saddle soap be ok?
Saddle soap is ok to clean it. But then you need to protect it with something and there are a million products to choose from. Actually, watching the Velocity channel I saw Mother's has some new leather cleaner and protectant out.
Spoke to a Mustang rep at Americade a few years ago and they use this http://www.protectall.com/palong.aspx
I've been using it ever since. Works great on Leather, Vinyl, etc
My Corbin seat is about 13 years old now and looks fine. I use whatever leather cleaner I have at the time. No need to baby it! The plastic around the sides of the seat take more effort to keep looking smart than the leather sitting parts.