Liberally sprinkling isn't really the best way to do it. What you really want to do is mist the oven and the bread with a spritz bottle, to generate steam, which in turn develops "crackle." In an ordinary home oven, it's usually a good idea to do it when you put the bread in, after 90 seconds, and again after another 90 seconds. It works best if you spray everything -- oven door, walls, floor, bread, and get the door closed as quickly as possible.
Worth repeating, open the door as little as possible and get it shut as quickly as possible -- you want to keep the temp high and steady when you start a bake.
Heavy thick crust sounds more like temperature issues, than water. It usually means the crust developed too slowly. But if you used way too much water, that might have kept the temp down on the surface. More likely you lost too much heat just getting the bread in. It's hard to diagnose bread problems without a lot of information, as there are loads of possibilities.
A baking stone, or any sort of temperature ballast (including a few fireplace bricks on your oven floor, might help. So might a really long pre-heat.
If it's a choice between misting and losing a lot of heat, forget the misting for now. Try doing everything possible to keep your oven temperatures high and steady, and see if that doesn't resolve the problem.
Another possibility, one more likely than not to at least be a contributor, is not getting enough "surface tension" on the loaf during formation. Another indication besides tough crust, is if your loaves lost some shape and flattened as they baked. It's very common.