It was astonishingly effective. After one hour and a half, the water was still uncomfortably hot to touch, and the loaves were ready to overflow their baskets. Handling them onto the peel and into the oven was quite tricky, but not completely unmanageable. For the second oven load, I halved the proving time. They were much easier to handle, and came out of the oven looking much prettier. When I tried the test loaves, though, I thought the first batch had the edge in flavour and texture, if not looks:
I really liked this loaf. I don't think the recipe is quite finished yet, but I thought the flavour and texture were pretty good, it's extremely wholesome, and we're still eating the last of ours 5 days after it was baked.