I've got two boxes of vintag Wisk powder as well. Mine are the "power scoop" version, perfume and dye free. Use about tablespoon with some STPP and oxygen bleach to do linens, and everything comes out clean. Used to add anti-foaming agent, but find even without it the product does not make too much foam. Will use the box that is open until it is gone, but am saving the other as part of my collection.
L.