Well, better late than...
Actually, the white glue method DID work fairly well, but I had to "up" the proportion of glue to water to about 1 in 4 before I started getting anything close to the result I'd been hoping for. Using nitrile medical gloves and then rubbing down the work while still damp eliminated a LOT of the "fishhooks"; allowing it to dry and then doing a spray coat of clear lacquer was nice, but not anywhere near as effective as a good varnish.
Eventually I just decided NOT to finish the darn things at all, allowing the customer the option of finishing it off to their own tastes. I also (re)discovered the fact that I'm still allergic to most paints and varnishes (my hands fall apart... almost literally!) so it turned into a "good decision" all round.
I also rediscovered the fact that when doing grafting or railings, indeed, any fancywork where you WANT the darker look of the old varnished items, a pre-coat with a 1# cut of your favourite colour of shellac will REALLY set things up. Cotton line takes the hue of fresh manila line (the old stuff... REAL manila) and gives the golden undertone that we used to prize so much when covering rails aboard ship. Funny how the memory just spills this stuff out after a strong jog, innit?
Anyway, the bottom line: Yes, the white glue/water works, but no, I'm still not impressed either by the surface hardness OR the tactile sensation of handling it.
Back to ye olde drawinge boarde! (Emphasis on the whinge!)