This one has a notch allowing the rocket to lock by rotating.  It's the most convenient of all tab designs & doesn't accidentally release.  

The thrust structure was cut open to allow ash to be poured out without destacking.  It still doesn't all come out without destacking & it's not as visually accurate.  It still has to be destacked to change incense sticks. 

Periodically, ashes fell outside the thrust structure so that was a fail.  It needs to be a complete circle.