OPsaks solved this problem for me, definitely!
I use two of them: One containing the fuel/stove setup that goes hiking with me; and the other containing extra Esbit cubes and stove parts that are staying behind. (All my stove parts have started to smell like the Esbits, so they all have to go into the OPsaks with the Esbit cubes).
You probably do this already, but: Cut the individual Esbits out of their plastic housing before you take them on your trip. I stack mine neatly inside a small Ziplock bag (which then goes into the OPsak) to prevent them from flaking all over. The plastic housing on a trip is a real pain; it has sharp corners that can cut your OPsak, it smells up your trash baggies, and it is unnecessary bulk and weight.
– Elizabeth