However, I would try to flush off the chemicals with plain water and let it stand before I added any more chemicals.
You have thrown a ton of cleaning agents at the grout in order to make the job go faster. The cleansers have probably broken down the grout and trapped the residue from the chemicals that are causing the reaction.
After you flush the grout and let it dry, I would then try the bleach. (overnight as Steve said.)
I would save the wire brush option for the very last resort because it removes the grout with the haze. But, you may have to do it.
Your fastest way to clean this right, may take time!