The only way to counter the effect of Ash Bone they need to sacrifice their breast by having Ash bone eat the chakra inside the breast and in this case Tsunade could survive while Sakura will become history
Mate 6PSM chakra cloak users can't survive a direct hit so I'm not sure how she does. I suppose if she cuts of the infected part and regenerates it, it's possible other than that I don't see how.
If we get more knowledge on it's composition and mechanics I'll be able to give a more definitive answer.
They die.... Anyone who disagrees is in utter defeat and living in fanfic.
Mind you i like and take both characters abilities into effect but they both die and that goes for anyone who comes in contact with ash bone killing technique
Yes. We've seen Obito's chakra rise from his ashes, so the Ash Bone doesn't destroy evaporate it or any of that weird shizzle.
You must be registered for see images
We also know that Byakugo is entirely automatic healing, so the healing must kick in ASAP as soon as damage is noticed by the body. As in, these signals are lightening fast and are sent to the affected areas' nerves the moment Ash Bone strikes.
Putting these two together, even Sakura's dusty, affected cells should have the chakra and signals to regenerate as her entire body is turned to ash bit by bit. This is assuming that Ash Bone just destroys each part once though. What separates her healing from Naruto's seal is that Naruto had to make a conscious attempt to heal and could only do so to an area as big as his hand and it didn't seem to be nigh instant either.
From what i can remember, those hit begin to disintegrate immediately and it suggests at least to me that it attacks on cellular level. They aren't surviving coming in contact with the bones.