Question: how are rocky mountain oysters prepared?
Answer: Split the tough skin-like muscle that surrounds each "oyster" (use a sharp knife). ... 
Soak in a pan of salt water one hour; drain.
Transfer to a large pot and add enough water to float the meat.
Add the vinegar to the pot.
Parboil, drain and rinse.
Let cool and slice each oyster into 1/4 inch thick ovals.