I also noticed the tires would turn a brown color after using Armor All. Thats on top of the dry rotting.
I like the Stoners More Shine. I havn't noticed any browning or dry rotting. Good durability also. Doesn't fling the dressing either. Soaks right into the tire like it should.
Duragloss makes a silicone free dressing also. Buts it more expensive. Around $8 while the Stoners is around $4.5. Michelin even makes their own tire shine. It even mentions how other protectants can cause problems like the ones mentioned in this thread.