Trying to maximise the oven rise of my loaf, and think I will try the steaming method, but what is the best way to do this in a domestic electric oven, and will could it damage my bread stone?
I would not go ahead and just toss water on the oven floor as this can both damage your oven, as well as lower its temperature.
Instead, I would use a baking pan with some boiling water, put it on the lowest rack. The temperature of the oven will keep the water boiling, and thus releasing steam throughout the baking.
You might also try baking a loaf of bread inside an enameled cast-iron Dutch oven. There's plenty of steam released from a loaf of bread that's being baked anyway, and the Dutch oven keeps it close, forming that delightful crust on the outside. I wish I could take credit for this one, but that comes from Ratio.
I use an old pressure cooker. I drilled and tapped the lid for a 1/8" valve with a "dip tube". I hooked 1/8" copper tube to the valve and run it into the oven. When the cooker comes up to pressure, I put the bread in the oven and open the valve for ~10 - 20 sec. This blows super heated water into the oven which instantly flashes to steam. No liquid water comes in contact with any part of the oven of any stones or the bread.
I use ice cubes on a baking sheet, on the lowest rack setting, as I want the steam to be gentle on the bread and it seems to me that boiling water would give off too much steam. I put in ice cubes in at the beginning and then about half-way through. Generally I am looking for a better crust on the bread rather than a rise though so maybe that is where the boiling water would be beneficial. I have used both baking stones and terra cotta planter bottoms and it did not affect or harm either.