I feed mine bugs n veg and the poo still stinks, thats what poo does ya know!
I started feeding the pellets on occasion a while ago and I didnt notice any difference really.
too much fruit makes for messy poo though. I dont use mutton bird oil for anything except rusty hinges, they "fly" after that!
seriously if they have runny poo constantly, somethings wrong.
Tell ya what though, shingleback poop is distinctivly stinky, really revolting. no idea why.