i used BS once, i shook it like mad, added half in the morning straight to the filter, rolled the foil backup, stuck it in the fridge and added the rest the next morning. had it totally cycled within 4 days. what little it had to take care of after that was minimal. i did not do WC's while it was working and the nitrites stayed below .05ppm as did the ammonia. barely detectable. make sure you have him IN the water for a few days before adding the BS though. you need food for the bacteria when you dump it in.
my real big concerns are septicemia and culmnaris. look both them up and see if it looks like what your fish has or if its just plain fin rot.
if you really wanna go all out, you can also catch small soft bugs like fruit flies or larva like mosquitoes and feed him that. try to get pellets in if you dont have any variety in his other foods. peas are great for constipation. as is epsom salt!
i woudl really hop on getting the antibacterial food and feed him only pellets over the next week or so. if it looks like the redness is clearing up, go back to your super foods when his redness either clears up or shows itself to being part of his natural color.
oh yeah and test his water before you change it, then you will know how high the levels are getting. maybe you need to do WC's twice a day. probably not but its always good to kjnow for sure.
id feel better if i could see a picture of him.
oh and i picked up one of
these a few years ago for my kids.... i shamelessly use it!! put a little tea bag between the fan and the cup, works great for getting little tiny bugs.
-ashley