If you can't get to a Dr. right away - I wouldn't put Benadryl on it - I'd put NEOSPORIN on it - it helps skin heal. I've never heard of using a "magic eraser" - are you talking about the "Mr. Clean magic eraser"? I think it says right on there not to use on skin. When I color my hair - I use witch hazel and cotton pads to get the hair color off my skin at my hairline and my ears right away while I'm waiting for the color to process. Good luck!