^^ I have used aluminum foil without glue. Just fold over many times/3 or more up and down and side to side, and crimp the seams tight with fingers. Pretty much no smell. Mylar bag is my choice overall.
Vacuum sealed, so if anything is passing through the bag, it's going in, not coming out.
This can obviously damage your green, so box the green first.
Still not happy? put your box of green, and also a sponge in the vac bag. Then if there is a leak, it will have to displace the volume of the sponge before you loose negative pressure in there. The sponge will basically act like a big spring.
Cheap no crush I do sometimes is vac the first bag loose, a bit of air but not snug, then pull full vacuum on the second bag. Keeps the flower in better shape.
^ Yeah and for even more protection you could put that in a big mylar bag with oxygen absorbers and heat seal it closed. And then wipe the outside good with alcohol.
Preventing smell is just the first step. If shipping, inspectors have been known to poke random or suspected packages with a device that detects certain chemicals or smells. I forget the name of it but I believe it has a long needle on it. So make sure your bags are protected by something hard that the device can't poke through.