The talk of museum coins in comparison to corroded slugs in your possesion on FAC is way off point. It is comparing apples and oranges; which is a logical fallacy...unless someone is suggesting that museums buy large groups of uncleaned coins (many of which turn out to be slugs) from places like eBay. I have many LRB's that are nothing more than corroded bronze discs and to suggest that they may have any sort of value is equal parts ignorant and ludicrous. Museums have coins that are very rare, or exceptionally nice or groups that were either found together or donated as a collection. I do not have any slugs with a provenance like a find spot, and that is the only conceivable way that they might have any worth--and that is debatable if you can't actually I.D. them.
The concept that every coin is sacred (Monty Python reference) is merely a romanticized notion and not even remotely practical. After decades of buying and selling, I have thousands of cruddy bronze coins...I guess I should open a museum.