If you have to pick up your dog poop outside, don't use the poopey bags, the smell comes through. Instead buy a box of the rubber dr.'s gloves and use that to pick up the poop. Then all you have to do is hold the poop while you bring it over and turn it inside out. Then tie a knot, done.
I can never smell anything come out after tying.
A good place to buy these is Costco or Sam's. I got 200 of them for $8.