I wanted to make the H2S cannister more reusable, and avoid the use of tape (which is not reusable and creates a mess over time). I used the hole drilling design suggested in another research note, but pre-drilled before running an experiment and used wide rubber bands as the method of sealing the holes. I tested the seal as follow: I blew forcibly into the capsule to test the seal, and it took a lot of pressure to get air to escape. I didn't test it, but I conjectured that this was more pressure than would take to 'pop' the lid of most of the cannisters. The rubber bands I used are from bundling vegetables at the market. I did look for wider rubber bands, but couldn't find a source for any. These allow for about a 3/8 hole to be drilled. I used a piece of paper with equidistant holes to mark and then punch holes that could then be drilled out. This was the best process I could find for consistent fabrication of the holes. A second tier of holes could also be added for additional airflow. I also used rubber bands to attach cannisters to a stake. Another useful option could be to use the same rubber band(s) that seal the holes to attach cannisters to stakes in the field - this could be convient (rubber band is always with the cannister) or a drawback (rubber band breaks in the field, now nothing to close the cannister).
This is basically a riff on the cannister design ideas, which I hope adds some useful ideas to the discussion.