This is what I started doing a few years ago. When I go into the restroom, I turn on the water and poo quickly. I then mess around with the water some more before flushing the toilet. That way, people think you were washing your face or something instead. It tricks my brain. As for the smelling part, I usually go before showers so it has time to chill out if needed.
Running water seems to relax my body. I'd try it.