As ace1 said it’s probably worth having a look on snowheads as there is a lot of info there (although there is no problem at all discussing it here I think).
There was a thread on Easyjet, it seems they did have a blanket ban on compressed gas of any kind and the only expectption was on medical grounds. It now looks like this has been revised and ABS/SnowPulse etc are also specifically exempt from the ban and can be carried in the hold. There was a letter from EasyJet posted on SnowHeads that is probably worth printing off and carrying.
I don’t own a device like this, but I am interested because if I did I’d be flying with it so have been following the threads on Snowheads. Whilst I can sympathise with ace1’s approach of “don’t ask don’t tell” (so to speak) I am not sure loss of the canister is the only penalty you risk. You could have your bags pulled from the flight, and you could then miss your flight and/or lose the bags in the worst case scenario. Also, I think the IATA and airline rules are pretty clear - if you tell them then you can carry these items, if you don’t tell them then you can’t…
One option, depending on where you are going, might be to rent a canister in resort. I hope that as these devices become ore popular this might be a viable and simple option that would save a lot of hassle.