Broke mine several years ago. Have a plate in and 4 screws which look like wood screws going all the way through the bone on the X-ray. Details of my recovery are getting a bit vague in my memory, but:
Only moving it hot water sounds a bit odd, but I’d say exercising it as per physiotherapist’s advice is the most important thing to do. If it doesn’t hurt (a bit) when exercising, you aren’t doing it any good.
I squeezed an indoor tennis ball when my hand was initially weak, then used a hard foam hand exerciser as it got stronger. Plus the physio’s rotating and flexing exercises.
I can’t flex my hand back as far as I used to be able to (my consultant expected that I would loose a bit of range), but it seems to flex further than my any of my friends’ wrists do!