I have a leather dash/interior as well, and was worried about using armor all due to the shine it leaves... and I've always found dust loves to stick to it a few days later (at best).
My dad actually gave me a bottle of this: http://www.turtlewax.com/shop/produc...tectant-20-oz-
No shine, cleans amazingly, conditions and also dust won't stick at all to it... Best of all- NO shine- and even without the cabin filter mod, dust won't settle on it for about 3-4 weeks. And I reside in a dusty place/use lots of dirt roads.
So far I'm happy with it and can see without any shine on the windshield, which is pretty darn important in my opinion.
I'm going to see what others suggest.
(note: no affiliation with that company or product, other than a happy user)