Thanks for the response. Magnesium sukfate is semi-soluble in alchohol, according to wikipedia. So filtering will get out some of the epsom, but maybe not all.
Now apparently you can make insoluble salts by adding sodium carbonate and magnesium sulfate to water and filtering off the now insoluble salts. That's water, not ethanol, but I figured it may point me in a direction.
Perhaps a time in the freezer will cause the magnesium to fall out of solution, I don't know.
I'll report back if I figure it out.
"Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods." Albert Einstein
I appreciate your perspective.