brown rot - can you save a badly infected tree?

[dimiessler]

I've been trying a softer, gentler approach to dealing with brown rot, and thought I had it under control last year - my peach trees (6 total, 3 varieties) looked like they were dying, then came back and bore hecka fruit after I sprayed with baking soda and then compost tea.

Now, however, they look moribund. I just pruned WAY back, but there's not much left after I cut off the diseased looking bits. And many of the branches have a brown do in the center. Does this mean the rot is in the wood and, if so, are my peach trees toast? Same thing's happening with rose bushes.

I'm inclined to use a nasty systemic fungicide, if it would save them, and then do penance for the rest of my life. Thoughts?