When I searched the forum for "cavitation," 226 threads came up.

There is an easy way IMO: replace the coolant at the recommended interval with the correct coolant.

As far as the Subaru thing, other than the poor spelling, I have to agree with others that it sounds contrived and the battery's proximity has nothing to do with the corrosion inside the cooling system.

However, if the engine had a poor ground to the body, and the battery were grounded directly to the engine, it is possible that there would be a different potential at the engine and body while driving/charging, and that could lead to additional corrosion. This doesn't appear to be what the Subaru blog was about.

On the Subara deal.... several things were red flags out of the gate... the idea that the battery placement or where the battery attaches to the engine would cause a head gasket problem ON THAT SIDE... due to coolant being more corrosive there... first off... only when the key is on is there any flow where increased resistance might happen... and how much time would the key be on without the engine being on and that coolant being run all through the engine cooling core ? And anyway.. almost all cars are grounded directly from battery to engine AND battery to body... a lot of magic thinking going on in that Subaru post...

I think that someone had a theory, and was able to find enough loosely-correlating anecdotal information to support the theory, ... must work for our government.

I used to have a Fiat X-1/9, fun cars BTW, and they did an interesting job of grounding the engine to a painted stud on the body. Lots of warranty claims for new throttle and clutch cables.

BINGO !!!! and they were very pleased with themselves for having linked all that ' evidence ' together...