Just about any containment setup should work. My Ejection Canisters are
pretty simple.
Two things to consider. First, some Christmas tree lights have shunts
so that one burned out bulb doesn't kill all the bulbs. Make sure yours
don't have the shunts or they will show continuity even if the filament
is broken. Second, check resistance. I have each filament connected to
an ohmmeter while I'm assembling Ejection Canisters, and if the
resistance varies a lot during the assembly process I throw out the
filament. When it's done I write the resistance on the outside of the
Canister so it can be checked before flight.
Doug Pratt
www.pratthobbies.com