I'm having trouble getting a small hand held device to work with new batteries due to deposits & leakage from old AAA batteries left in too long. Tried scraping with a needle. Any products I can brush on that can remove these deposits and make the connection again? It's kind of small and delicate wiring I don't want to fiddle with it too much for fear of ruining it altogether. Thanks
Steel wool or even a ktichen scrub pad might do what you need. Also baking powder and water will remove battery acid. You could use a Qtip to apply and then wipe with a moist cloth to remove any residue.
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.