Farts are supposed to stink, it's for benefit of the people who don't hear them.
I've used supercoat for years without any probs.
I mix kangaroo mince with it most days & vary sardines, eggs, cheese etc regularly. A splosh of olive oil occasionly doesn't go astray either.
Dry food can cause constipation, so if you are getting daily "results" you don't have a lot to worry about.