Mine have only ever had 1 greenie each, they have only just come over here, and they are very expensive and not very big and they didnt go mad for them so i wont get them again.
They get raw hide chews regularly iv never had proplems with them, but there best treat and teeth cleaning comes from regular free whole raw legs of cow free from our local slaughter house! they go mad for them and best of all no running poo's!

although rio has to have them cut into smaller bits because she only has 1 K9 left and 3 bottom insissors but can still manage them!

Ky