^Some people flush their MG soil before using it, for the same reason, to wash out some of the nutes. I never tried it, so can't say much more than that. Also, I should mention that most of my Crystal plants turn out perfectly fine, except for one here and there. Maybe the OF has hotspots in it, like it isn't mixed well enough? Hmm....
Or, you could go buy a bag of cheap soil, and mix it half and half with the OF. That'd help. Add some more perlite too, that'll make it easier to wash out any excess nutes, if it becomes a problem again. Also, you'd be better off in a bigger pot. Maybe my "hotspot" theory is right, because I never have that problem once I move to 1 gallon pots. My theory there, is that the plants have room for the roots grow outwards from the toxic area, saving itself. They're pretty confined in those pots you have, and if the soil's hot, it's hot, no room to go anywhere else.
