Doug White fired this volley in
:

Before that, I had some success making my own seals from nylon rod
stock. It's just a short thick tube that press fits down inside the
pistol. There's a steel valve stem with a conical face that seats
against it.

Doug White

What about just coating a spiral tap with a heavy grease, then threading it
into the seal, in order to draw it out all in one piece? The spiral tap
will draw chips UP into the grease, where they'll be held.

Lloyd