The known anti fungus-meds and antiobiotics are "designed" to treat infections on (and some in).fish bodies. They "help" the body in case the natural immunesystem can't cope with "attacks" from outside.No, the title remains the same.
I AM beginning to wonder if I'm wrong as to the problem being a toxin rather than fungal. I still lean toward a toxin but, after all the fish were dead, I introduced a small deer antler to test as to if it would affect my PH. PH didn't change but, after 5-6 days the antler developed white 'hairs' all over. That seems fungal to me. Should have taken a photo before removing the antler but didn't think.
I still think the likely culprit was a toxin but it is things like the above that make me want to dose with anti-fungal and antibiotics before flushing and recycling. Once I've done the antibiotic and fungal stuff I'll also add carbon to the built in filtration chamber which should probably do nothing but I want to cover all bases.
Funny thing is that I just may spend more trying to save plants and decor than I would spend totally starting over. Then again it isn't a matter of cost as it has become personal.
It is useless to use them for the use you're describing. The misuse in this way might damage bacteria (that are always around) slightly and help them to make themselves immune for moments as decribed (infections). Also the natural balance in a thank is gone for some time.
Short : Don't do so.
If you want to this use a desinfectant (not advisable either btw).
Simply flush / waterchange and start with a small amount of fish.