Introduce Nitrous Oxide canister refunds

I volunteer to litter pick in my community in Rochdale because a more direct approach is required to tackle the UK's very fertile throw away culture. The abuse of NO2 is becoming a considerable health hazard and equally the littering left behind in the use is getting ridiculous. There are plenty of recyclable materials with these canisters; incentivizing the public or users to collect them and dispose of them safely for a refund would see the UK picked clean more regularly.