Try this,
Neutralize all acid on top of the battery, then Dry.
Spread a thin coat of vaseline or silicone grease around the offending post and cell then keep going to the nearest negative conductor which may be a battery hold down frame or strap. On a seemingly dry battery top I use diluted phenothalien and water pump spray. Acid reside will turn the solution bright red. Some spray cans of battery acid neutralizer will do the same thing at a higher cost.
Most of the corrosion you see on terminals is not from the lead. It's from the steel fastener. Somewhere here or at home I have boxes of 316 stainless steel bolts, nuts, and spacers. It ignores the corrosive effects of H2SO4.
My batteries have K Monel fasteners rescued from a scrap metal yard in Wilmington California. I cannot remember what I paid for them but it wasn't cheap 40 years ago. My 25-year old K-car has the original untouched battery cables.
