Something I have tried recently is the tin from smoked oysters. I used one of those "safety" can openers that does not leave a sharp edge. It works by separating the seam, so the lid fits back on perfectly. I have used both the hand cranked and electric versions. The hand one allows for a little more control. The can is then washed out thoroughly; I have not had any problems with residual odors. The oblong cans are easily sealed with electrician’s tape. If one wanted to go through the trouble it could be solder all the way around. I recently purchased some tape that is supposed to create a waterproof seal. The tin is slightly smaller that an Altoids tin, but one advantage is that they stack on top of each other well because of the rim around the top. Pete