I have tried durian favour, taste exactly like those durian cake(sticky type of kuah in long shape which you can buy in provision shop). I believe they use the same favoring as well. Do note favour is strong, it will stay longer in your carto longer than other favours. When I switch favour, normally it takes only a few puffs and I can taste the new juice(of course I already ensure there are not much residue left before adding in new juice). for durian, the smell is still there after I empty a fully filled carto with new juice.