I left the baking soda overnight and then vacuumed it up but the carpet still smelled! I shampooed the carpet and that seems to have reduced the smell somewhat, but it is still there. I think I will shampoo it again later and then maybe try one of those scented powders that you can vacuum up.

I am getting very depressed about this! DS has a lovely carpet and I really don't want to/can't afford to replace it