How can I effectively remove a stain from wood without using polyurethane?

To effectively remove a stain from wood without using polyurethane, you can try sanding the stained area to remove the top layer of wood and the stain. Another option is to use a wood stain remover or a mixture of equal parts vinegar and water to help lift the stain. Be sure to test any method on a small, inconspicuous area first to ensure it does not damage the wood.