I think a standard flush should get everything out of the lines. If the DOT 5 is lighter than water (and presumably lighter than the glycol based stuff, I'd assume that the DOT 5 would rise to the top of the cylinders and be flushed out of the bleed port. If that were the case, you'd see DOT 5, then any water that might have accumulated (not likely for a recently filled system), then the glycol based fluid. But never having done that, I'm not sure.
That also assumes that the cylinders don't need rebuilding. With no real way to tell if the seals were compatible, I'd rebuild everything to be on the safe side. Brakes are something you should be able to depend on. "That should work" shouldn't apply to brakes.
