Well, I think my first question is, why did you wash it with soap? If you see those teeny tiny hairs projecting off the very small adventitious root, those have probably been damaged by that treatment. You cut looks good, it looks like you got all the rot. Did you trim off the broken end of the longer adventitious root? If you didn;t you should,just above the break.
I would treat this with fungicide, and plant it in a small container just large enough to contain the roots, in a substrate of damp long fibered sphagnum moss. DAMP. NOT wet. Keep it damp, warm, in bright light. The remaining rootstock should begin to grow new small roots (this is how adventitious roots in epiphytes and hemi-epiphytes work) and after you can seen them running through the moss, and hopefully you see a new shoot emerge up top, you can transplant the whole moss plug into a nice well draining small pot of aroid-friendly substrate
But please be advised....you have to be PATIENT. This will take time, probably quite a bit of time, because not only was this damaged in shipping, it was also traumatized by the soap wash. Don;t be tempted to pull it up out of the moss to 'check the roots'. Leave it be. I think it is a viable cutting, but it won;t be if you monkey with it too much
