[Oncidium] Erwinia bacterial soft rot- should I cut more?

[Pècèl lélé]

One of the new growth of this Oncidium Heaven Scent 'Redolence' was yellowing, becoming slimy and exuding foul smell so I cut it to the base (along with the root), then I soaked the whole plant in 3.5% H2O2. But as you can see the rhizome I cut the new growth is reddish
inside although the neighbouring pseudobulb looks healthy enough, should I cut it altogether? There is still faint stale smell coming out. There are also black spots on the other new growth and the leaves are yellowing too with some brown spots.
As you can see this Oncidium barely has any root and the rhizome looks black, is this even salvageable?

This rhizome nears my index finger looks reddish:

Zoomed pic of the same spot:

With neigbouring pseudobulb base showing (it have some brown spots):

Bases of other pseudobulbs (they also have brown spots):

The other new growth have brown spots too:

Yellowing leaves with some brown spots:


(I tried to upload some media here but it failed saying no security token or something, I uploaded it to Imgur and embedded it here but if it also doesn't shows in the post here's the link (sorry): Oncidium rot - Album on Imgur)

[Ray]

Treat with a copper-based bactericide. No more cutting.

[rbarata]

Note that Oncidium Alliance plants are prone to get spots. Your plant, comparing with some of mine, doesn't have any spots.