I would not use Alkaline batteries in anything of value. They are all capable of leaking and destroying valuable equipment. Eneloops for everything that's AA /AAA & not a throw -away.
Amazon has an energizer metal led light for about 9 bucks (EVEENML2AAS) 35 lumens and an 1.5 hour runtime. Push button tail switch. It comes with 2 alkalines, but you can buy a dozen Tenergy low self discharge AA Nimh for about $20
The question is how many chargers you need to buy. If kids...
The best stuff to use to clean up corrosion is the 100% solution that comes in 2ml tubes.
DeoxITLiquid, squeeze tube 100% solution 2 mL - D100L-2C
they're small but go a long way. About 8 bucks.