Btw, lanolin is an excellent product to protect electrical installations as well (after installation and not on actual switches, relays etc.).
Lanotec products is non-conductive to 70kV (70000Volts), so you could spray your battery terminals with it no problems, as well as any circuit boards (in your car, your computer or that phone you constantly take with you in your dinghy).
http://www.lanotec.com.au/?link=12(click on the "electrical", "automotive", "marine", and "timber" tabs at the top)
