Can (or should) I use regular armorall on my leather seats?
So long as they aren’t bench seats it’ll be fine. Some of my friends even use it on their motorcycle leathers and it hasn’t done them any harm.
It won’t hurt anything, but if you have bench seats or low bolsters, you’ll slide across the next time you turn a corner.
A better product for leather is Lexol. It conditions the leather and actually helps to “heal” small scuffs and scars. It comes in a brown spray bottle and is available at most auto supply stores.