Vivitar Flashes Great Flash For The Money Aquired A Used Vivitar Flash With Battery Corrosion. Can I Fix This?

Aquired a used Vivitar flash with battery corrosion. Can I fix this? - vivitar flashes great flash for the money

The corrosion seems minimal. (I've no doubt seen and repaired a lot worse.) I thoroughly cleaned the connections with my Dremmel, but to my surprise, he's still dead as a door nail. Can unseen internal corrosion could not be cleaned outif I take all the pieces? He came with a rich harvest from Canon and I'm dying for them on the right track. I prices rise to new and forgotten. I'm broke as a joke. Ideas?