I was going to start a new thread, but remembered this one… Mods do as you see fit 
I figure everyone is at home looking for backyard crafts, so a revival of this theme could be justified.
Exciting news. It can be done! So far I’ve created test swatches which are ‘monks brown’ from white cotton and ‘Dhammasara brown’ (chocolate) from my very faded work-robe. They are curing and smell amazing (and a the texture of ‘crusty cardboard’).
My first test, I started with instructions from ACT textile artist Sally Blake and her colour database for eucalyptus dyeing. I used the leaves from Eucalyptus Wandoo and rusty bolts, and had successful results on wool but couldn’t get the colour to stick to cotton. Maybe if I’d cooked the dye to ‘crude oil’ it would have been deep enough.
Then recently, I was inspired by the monks at Abhayagiri, who are now dyeing with their local Madrone tree bark and thought I would have another go. I had a short correspondence with them for some tips, and then a great journey down the rabbit-hole of internet research, to discover that the very tree that causes me much hay fever dukkha is the answer. The Marri tree Corymbia calophylla, which apparently is not a eucalyptus, oozes a red sap (Kino) and has a beautiful dark bark and boiled up to a much much thinner dye than Bhante describes produced promising results (no iron or other fixative except soy milk).
Bhante @sujato, was this roughly the amount you remember using for a triple robe set?
I have photos saved on my tablet of what I have achieved so far and have documented my method (a variation on Sally Blake’s) which I can share if people are interested. I’m still very much in research and development mode. So if anyone can recommend resources specific to eucalyptus (or other high tannin trees) dyeing I would be appreciative.