Synthrapol is available at many quilts shops and online from places like Dharma Trading and ChemPro. It's quite inexpensive, and a small bottle is enough. Synthrapol is designed to suspend unset dye particles in water so they can be washed away. It shouldn't affect the Sharpie. It may take several washings, though, to take all the red out, and I would not dry it in the dryer or in any heat for fear heat might set the red dye in the bleed.
If Synthrapol doesn't get it all out, I would probably make up a strong solution of Clorox 2 and dab it on the affected areas, let it stay there for awhile, then wash. If absolutely desperate, I might try the same with diluted bleach (but that gets pretty dangerous).