There are about 130 billion pennies currently in circulation
That’s more than 716 million pounds in pennies. The Mint produces 5-16 billion pennies every year. Coins that are heavily damaged are typically removed from circulation.
Seems like there literally aren’t enough pennies in the US for him to do that…
Edit: me dumb, math hard. But at the same time, good luck to him getting the pennies out of everyone’s change jars…