Leakage from 'alkaline' cells is a bit different and the use of either vinegar or lemon juice will neutralize the crud. Yes, bicarbonate of soda is what to use on an 'acid' based lead battery.If all else fails. Brush the offending parts with a solution of bicarbonate of soda then wash well with de-ionized water. Allow to dry in a warm place for a couple of days then spray with WD40.
I lived and worked through the era of lead cased cells and they would leak and corrode TEN SECONDS after their charge had gone!
Dave.