I gassed my first couple of mice yesterday. While it's not easy it needs to be done for the greater good & also to relieve my wallet.
Knowing it was humane and not watching them suffer made it easier. I don't think I could throw them at the ground or CD efficiently enough to give it a go. Luckily all my snakes are now big enough to accept food items big/old enough to gas.
I did have one question though and shall ask here for the benefit of the original poster & anyone else curious:
When the co2 was introduced it did take a while & I feel that 'feathering' the sodastream resulted in better dosing than big bursts. However I did witness increased heartbeat before they went to sleep, is this normal or was my dosing incorrect? Increased heart rate was witnessed but no discomfort.
I also found initially I put to many 'outlet' holes in the chamber as I was worried about blowing the lid off. I used holes about 10% of the inlet and about 6 of them but I taped most of them up.