It would be nearly impossible to deliver a regulated 20% replacement of atmosphere in the first blast and deliver an 80% replacement of atmosphere with the second.
You'd very likely get the 80% replacement first and animals that ARE stressed by the process.
__________________
- Ssthisto
"My bum has been a bum for a very long time, but that doesn't mean I have to listen to what it says."
- Terry Pratchett, Fifth Elephant
i can't see why putting them in a sealed container would be any worse than using co2? slower yes but as they just drift off to unconciousness then die this doesn't cause any panice as long as the box isn't too overcrowded and has some shavings in the bottom. i did this by accident taking my pet babymice to a pet shop when i used to breed them as a kid and there were no marks or anything on any of them. and if they panic they damage each other. they were simply lying there dead???
sounds a silly question, but can you c02 your rodents in the house??? wont affect anything will it?
If you use an unregulated CO2 source - like vinegar/bicarb - you CAN wind up dosing yourself with it as well as actually doing what you intended.
I would definitely recommend a canister with a regulator so that you can control how much gas is released and don't stick your head in the container - but other than that, your house already contains CO2 and adding a LITTLE more to an enclosed space (the mouse container) that is further enclosed within a room is not going to do any harm. Just keep pets and small children away from the container while it's in use.
__________________
- Ssthisto
"My bum has been a bum for a very long time, but that doesn't mean I have to listen to what it says."
- Terry Pratchett, Fifth Elephant