I'm a little late here, if you know or have access to a Commercial/Industrial electrician or facilities maintenance person, ask them about contactor paste or something to that effect. My dad used to work for an electrical wholesale outfit and he always kept a 10-12 oz. squeeze bottle of a black paste ( can't remember the brand) and all he did was put a thin coating on the battery posts/terminals and use a small brush to lightly cover the cable ends once installed and never had any issues with corrosion.
You will never have corrosion on the battery cables or connectors (battery clamps) with an AGM.I have AGM batteries in the Honda and Buick seven years now, no visible corrosion yet. I still clean the terminals every two or three years or so to brighten them up, then a quick shot of terminal spray. The AGM batteries are were average priced, not high end ones.