I had a very nice Ricoh flash unit damaged this way.
I never found a solution (pun accidental)


depending on battery brand, there may be an anti-leak warranty - this
warranty is why I stick to the major brand batteries for anything except
disposable flashlights - it's not that the batteries don't leak, it's that
when they do, the Mfgr will fix your unit, replace it, or give you some $
for your damaged goods.