So instead of the customer sending you back hodl butter jar. They keep hodl jar and you send them a refill.
They clean the hodl jar they have.. then squeeze the new refill into jar for safe keeping.

If you buy a fancy tea. They come in a great display case. Then instead of buying the display case + tea again.. the company sells refills at a lesser cost.

Idk how well hodl butter stays fresh, or unfreezes. But perhaps you can sell bulk this way to. And provide a protocol for defrosting and refilling into hodl container.

The economies of scale and shipping sound like they can make sense for both you and customer.