Unfortunately ash is not well behaved when unprotected, unvarnished or (to put it mildly) actually used. The result of such exposure is shown in the photo. Yuck.
This means that every so often (a.k.a. too often) folks like me take the wood down to bare wood and start over. Here's what this process look like after perhaps 3 or 4 delightful hours on one's knees.
The next step is to recoat with varnish. In our case we went with 4 coats of (cheap) varnish, followed by machine sanding. This provides a base to allow the final varnish coats. I decided on 3 additional coats (for a total of 7), and found the result more utilitarian that glamorous. Works for me.
And finally the result: