We’ve never made that substitution, so we can’t speak to that. You could make just a small batch and see how it works.

I’ve found that it thickens up for me overnight, but it should still be usable.

I use mine in an HE washing machine with no issues.

We’ve never used it in HE washing machine so we can’t seek to that. As far as it going bad, we’ve had it last for several months without it going bad, I don’t know that there is a standard answer.

Does it work on HE washing machines?

Sometimes that happens. I just stir it with a large spoon to break it up a bit.

I add a squirt of dish soap for removing “super” grime that’s greasy and spray oxyclean on spots that are non-greasy stains. Sometimes if there is a particularly tough greasy spot, I’ll scrub it with dish soap before washing. This works even after the item has been washed and dried, you just have to wash it again after scrubbing.