Lupo Battery Cable Insulation Fails: Safety Risk?

Hello everyone,

Here's the translation:

'Another problem already. This time, it's my mother's Lupo. Last week, I was shocked to discover that the cable insulation on the wires leading from the positive terminal of the battery is completely corroded. I'm not talking about damage from rodents, but rather corrosion caused by battery acid. I've been wondering for a while why the battery hold-down clamp at the bottom is so rusty and everything in the surrounding area is heavily corroded. There's nothing missing from the battery that could have leaked out. Also, nothing has happened to the battery in the last 3 years; it hasn't been replaced due to a fault or anything like that.'
Does anyone have any idea how the damage could have occurred?
Does anyone know how to potentially salvage the cables leading to the central electronics and starter motor, without having to replace the entire wiring harness?

Regards,
DENNIS.

Okay, here's a tip for you:
Try holding the oxidized connectors in boiling water.
(It should work with a small container).

I got the tip from a colleague, but I haven't tried it myself yet.