On the odd occasion that one of our cleaners has broken something then the item has been replaced 'out of our own pockets'. We do not do home cleaning, and I would guess some of the ornaments you have to clean around are expensive, so be careful!!
I would think that for what the insurance companies would charge for cover then it might be worth taking the risk and not having any. In over 5 years trading we have broken a couple of objects worth about £50.00 in total. So we have probably saved hundreds if not thousands on insurance.