I love Evaporust!

I tried same thing, it goes thru a chemical change and loses its strength. Key is to use it warm and fill as many voids as possible.
Have to get creative with trays/containers/tubes. For example don't use a gallon to clean a wrench. Use just enough to keep part saturated.
5 gallon pail here is over $100, so try to make it last.
I do like it and I've used it a good bit, but so far, I've not figured out how to keep it from losing its strength and it loses it pretty quickly. I've tried straining it too. I'm beginning to wonder if maybe I got a bad batch.