Saving Money Permanently Boosts My Stats: What's Wrong with Hoarding a Little Extra?

[2. You only have the right to use, not ownership, of the interest in the Demon Piggy Bank. Well, the interest gold coins only have the right to use them but not the ownership. If you put them in, they don't count as your principal, right? Is there a systematic way to consume gold coins later? Otherwise, even if it is washed and circulated, you will still receive Demon Gold Coins, and eventually they will all become Demon Gold Coins.