I'm not a vet, Phillip, so what is right or wrong is not for me to decide. That's your call.
I have had success (twice) feeding NLS Hex-Shield, but I don't know how much your fish consumed (you also questioned that) over the period that you were feeding. I fed twice a day, and fed the hex formula exclusively over the duration of treatment. Most aquatic experts in this field, including Edward Noga, recommend the use of metronidazole to treat HITH, which is one of the primary ingredients in that NLS formula. Having said that, even if the initial cause has been eliminated in the gut/organs/blood/etc, those pits in the head aren't going to heal overnight, and they may need some additional meds to stop the necrosis. In that case, yes, I would personally try spot treating, or a dip/bath, in meth blue as was recommended by Dieselhybrid. There are other options, but that is a good place to start. Most fish will bounce back with just clean water, but your fish might not fall under the category of most.
I have had success (twice) feeding NLS Hex-Shield, but I don't know how much your fish consumed (you also questioned that) over the period that you were feeding. I fed twice a day, and fed the hex formula exclusively over the duration of treatment. Most aquatic experts in this field, including Edward Noga, recommend the use of metronidazole to treat HITH, which is one of the primary ingredients in that NLS formula. Having said that, even if the initial cause has been eliminated in the gut/organs/blood/etc, those pits in the head aren't going to heal overnight, and they may need some additional meds to stop the necrosis. In that case, yes, I would personally try spot treating, or a dip/bath, in meth blue as was recommended by Dieselhybrid. There are other options, but that is a good place to start. Most fish will bounce back with just clean water, but your fish might not fall under the category of most.