OH Robert
its not looking good BUT i NEVER toss any until i am sure nothing can be saved. IF it where me i would get an ice cold beverage of your choice sit down out side with a good SHARP SHARP knife and CLIPPERS. use alcohol or peroxide to clean the knives and clippers. I would start on the smallest farthest ends of the roots and start cutting. and keep cutting until you see 99% good white/green root. do that to all the tangled roots. I say 99% because i clean my clipper or knife just after that cut and make one more cut for a good clean cut.... then i have been told to dip it in peroxide and see if it bubbles like it would a cut if not let dry part way and cinnamon.
If there is any of the root system left its not a lost cause. branches can also be planted also. It is hard to let anything dry out now because everything needs water is prime growing so it keeps using the storage it has. there are a few people that try to seal plumeria with a torch i am going to try this to seal it, I am going to heat up a piece of metal red hot and hold on for a few seconds just to cauterize and not cook the flesh. i have been dipping my adenium cuts in rooting hormone
i have an idea for a rotted caudex and it is set the caudex on pea gravel and take peat moss damp and cover just the edge of the cut on the caudex so no moisture reaches the inside but is on the edge to try to stimulate root growth, have not tried it yet but just a theory im thinking about. in a pic i say how stems root they root on the outer edge not the center of the branch keep it dry it wont rot???
It looks like you will be left with the top and maybe a small amount of root system
good luck
