Bleach can melt soft plastic and could do real harm to your filter and sensitive components.
Since that disease has not been positively identified I can suggest starving it: Bacteria that isn't completely dead will go absolutely crazy trying to stay alive, splicing genes like nobodys business trying to find a gene that will let it continue to live and breed. That is why people that stop taking antibiotics before the infection goes away often get even sicker than before.
So I suggest boiling water and a softer antibacterial agent plus several weeks dry time to eliminate any 'dormant stage' bacteria would be best.
I cannot tell you what bleach would do to a fish..I only know about bacteria
. Any experienced fish keepers please feel free to correct me.