I use epsom salt to help actual acne, and lemon juice for scars. It really makes a difference with scars. My scars drastically improved within a week, it was crazy.
I had moderate acne, tried epsom salt. I figure its the salt, possibly also my face routine, but it really does help a lot. I use skintactix facewash, dry my face then use a slice of lemon to wet my face, use epsom salt and kind of scrub it into my face, use some water if its too rough, then leave the crystals on my face for 15-20 minutes, rinse it off, use organic coconut oil as the moisturizer, tiny bit or else its too oily, then use skintactix toner and green tea poultice. i only do this routine once a day and wash my face normally the other time. It has gotten rid of all my acne, i give credit to the epsom salt/lemon mixture because i did the rest of the routine before and it doesn't really change anything drastically. The whole "gets worse before it gets better" saying applies here too but unlike say proactive which made me break out for some weeks before I quit it (never got the chance to see if it works eventually), this made me break out for 2 days then it cleared up. so glad I tried it.