I had someone explain to me a simple way to do it.
Soak in muriatic acid for about 24 hours.
Dump the acid and soak in fresh water for up to possibly even a few months.
Change the water every few days, when you see the little puddles of...er whatever that is that's coming off and floating to the surface.
This will work great for glass and metal items, but what about wood?
Of course assuming it's not half rotted away from all those years under water.
What do you use to clean wood?
I have a feeling the acid would just eat through it.