Some people are their own worst enemy.
Over the years I've done my share of camping, although not for some time now. A fellow camper/hiker linked a video to a forum I'm on showing how to refill a disposable gas canister from a camping stove, the process involves a sort of screw gadget and holding the cylinders together rather like refilling a gas lighter. The difference being theres a lot of gas involved and the canister your trying to refill isn't designed to be refilled.
I'm not going to link the video because it's downright bloody dangerous, and personally I think anyone even trying it must be bonkers. Lets face it the canisters are not expensive to buy in the first place, only a couple of quid.
And more importantly I've seen what happens when gas goes wrong. I had to drive a very badly burnt man to hospital after he blew up his lorry, blew all the windows out and burnt out the inside, he was badly burnt too, he was just changing an empty (or so he thought) canister and it exploded.
He was lucky, he survived, but the 4 people in the house near where I used to live didn't, that was gas again, it blew me out of bed, took out pretty much all the windows in the street and took 2 normal houses down to the level of the downstairs windows.
So please don't mess about with gas canisters, yes you'll save a few quid but it's properly dangerous, you won't be able to refill them fully anyway because of pressure equalization and they are not designed to be refilled, the valves may leak after.
Darwin was right, I suppose it's natures way of culling the weak and mentally challenged of the herd.