Is there any way to PERMAMENTLY eliminate rear main oil leaks?

If you do not want your oil pan [ & many otherts ] to leak.........use silicon. The last time I used cork or similar was.....I think...1982...or was it 1983. Silicon has special properties that other gaskets do not have:
- up to 650* working temp
- never goes hard & dries out
- has some elasticity such that it moves with temp changes.