UPDATE for the interested. I am now reasonably competent with the 'shavette' - in fact I was camping this weekend and felt very pleased that I was able to shave using the shavette, a bottle of glasses cleaner, which I'd filled instead with olive oil and water, and the wing mirror of my friends van. Because the blades are so sharp, you can shave without softening the bristles with hot water if you're just neatening up - the olive oil & water mix provides enough slip.
I am now at the point where I sometimes open up old wounds from when I was learning, rather than creating new ones. That's progress. I might lay off it for a few days to let everything heal. However, having started the post suggesting I only needed to shave weekly, the new closeness of the shavette tells me otherwise. Turns out I was just a scruffy sod. I should also add that I've bought an alum styptic pencil, which is very good.