Robert, thanks for posting this. We also have well grown docken here (mainly Rumex obtusifolia I think). Your post inspired a bit of interweb browsing and I found quite a few other foraging 'blog talking about using seeds for flour. Some ground the whole seed, and some rubbed off the husk after drying.
Eat the weeds blog has lots of suggestions in the comments about cooking the leaves to remove some bitterness, and some other recipes. I haven't tried it yet, but I think I may well next year....