This is an interesting idea, never heard of it before.

A little googling produced this snippet from "ESCULENT FUNGUSES OF ENGLAND"

The Polyform ... makes a razor-strop far superior to any of
those at present patented, and sold with high-sounding epithets, far
beyond their deserts. To prepare the Polyporm for this purpose, it
must be cut from the ash tree in autumn, when its juices have been
dried, and its substance has become consolidated ; it is then to be flat-
tened out, for twenty-four hours, in a press, after which it should be
carefully rubbed with pumice, sliced longitudinally, and every slip that
is free from the erosions of insects be then glued upon a wooden
stretcher. Cesalpinus knew all this, and the barbers in his time knew
it too, and it is not a little remarkable that so useful an invention
should, in an age of [something garbled], advertisement, and improvement, like our
own, have been entirely lost sight of.

Sounds like a lot of work, but it might turn out to be a cool project.