i read this on another site..im not sure if i can pot the link but here is what it said
"An aquarium that has had an outbreak of fish tuberculosis should be meticulously cleaned out with bleach and left to dry before you restock it. "
i think using bleach and even rubbing alcohol to wipe things down will help.the alcohol will evaporate not leaving anything behind of it..i watched videos on youtube where a professional used alcohol to clean down areas of broken glass and put a new piece in it.i too did the same with a 15 gallong hex tank i fount..though no fish are in it currently..
you can also run the tank in a dishwasher cycle with no soap.the plants if they are plastic,you can boil to kill off the germs..though im not sure about boiling gravel.i assume you can with no affects to it and that will clean it also...the filter cartridge i would through away and buy a new one.as for the filter case i would either use bleach or alcohol on it or possibly run it in a dishwasher as well if its capable of handling the heat..
here is the link anyways where i got the info
im kinda in the same situation.except i dont know exactly what my fish had when they died.and im not sure if i want to completely clean it out and start a new cycle or just leave it as is.thought about getting some rosy red minnows(fathead minnows) as a tester fish since they are so cheap and are used for that.though id rather keep them as pet fish..
personally i would do a real good clean of it using as mentioned..and completely let it dry,if you are in a hot area and can do it.id let the tank and stuff sit out in the sun.i live in phoenix arizona so the temps here get over 100 F several several days in a row.