This is an interesting post, and it's gratifying to hear about customers requesting a "driftwood" look as that's an effect I've been pursuing for several years. Here's a few things I've found work for me,
1. Two part bleach is the only bleach that gives me the effect I want. I tend to use it for shorter times than recommended, but then again I'm generally working with lighter timbers to begin with so I'm only using it to knock back the colour a shade and to remove the yellow/orange cast that most woods have to some degree. Don't neutralise two part bleach with vinegar if you're using poly/acrylic finishes, just wash down with plain water.
2. Avoid any oil or varnish finish like the plague, they give a yellow or orange tint to the wood which is something I'm trying to avoid at all costs. I don't have spray facilities and I use either a thin coat of bleached shellac or a matt poly/acrylic water based finish for surfaces that need more protection. Both of these routes preserve that pale bleached look without any yellowing.
3. When I'm arranging boards I often try and include a thin sapwood band on mating surfaces. Besides giving an almost invisible glue line that makes the individual boards look twice as wide, it also looks like "surfer's hair" with bleached out streaks amidst blonde hair...it's a pretty effective way of giving a "coastal/summer" look to furniture. By the way, oak, elm, and olive ash are my favourite woods for this effect.
4. I try for a matt effect with the tiniest hint of sheen. That's easy enough with shellac but harder with acrylic. Even though water based acrylic dries fast it still takes a couple of days to really harden off, and if you use too much pressure too soon (even with a tack rag) you can burnish the surface to a satin effect which is too glossy for my tastes.
5. I use a sanding sealer on open grain timbers otherwise I can't get the smoothness of driftwood. I realise many people avoid sanding sealers on surfaces that are exposed to wear, but I've had table tops that have stood up to six or seven years of family life with this procedure and no problems so far. To get the smoothness I want I'll often sand down to 600 grit, which would be pointless on an open grained timber with sanding sealer. In the future I'm going to experiment with natural edge timbers, and I'm planning on wire brushing the edges which I believe was the George Nakashima approach, apart from this I'd avoid any attempts at distressing.
6. I've experimented many times with liming to try and get a slightly salt encrusted look, but despite using all the usual formulas I've never been even remotely successful, it always ends up looking either contrived or just plain nasty! If you find any liming technique that works better please let me know!
Best of luck.