I don't like the salt flushes either, I just eat the celtic Sea Salt on what foods I feel like. I love it on fresh popped pop corn over the stove, with just some olive oil for the popping process and then some Sea Salt sprinkled on top.\
Go with you intuition, ask your questions, take what you want and leave the rest.
I personally am loving the magnesium and vit-c at night, for me it does what the salt flushes do for other people.
You say a test shows you are low on Potassium, then I would find a source and give it a try. If you want to calculate food sources for their content try fitday.com it's easy to use.