Totsuka sword would just seal away the flames, wouldn't it?
Just like Jiraiya sealed away the flames in a scroll.
Totsuka sword > scroll xd
Also, let's compare the two swords:
Totsuka sword -> no escape, your @ss is sealed!
Amaterasu sword -> only chance of escape is to use something like Oro's disgusting body-shedding technique (like Sasuke did in his fight w/ Itachi)
contrary to popular misconception they are both equally as deadly. they both can stop edos although in different ways. the amaterasu sword goes through you so you get cooked from the inside out. so basically they are both one shot kill weapons. but people will say bla bla bla bla its the totsuka blade its legendary. that is irrelevant as it has no advantages over the amaterasu sword.
amaterasu sword wouldnt affect susano