Not sure what you are buying this for...maybe for the New Year count down? hehe..
Alternatively you can try and contact some of the mountainbike shops. I have one airhorn which does not allow an attached disposable portable can of compress air but it comes with a clear PVC bottle that you use a bicycle pump to pump it full of compress air to "recharge" it. It has a button you press to BLAST the heck out of it hehe. I use that for my mountain bike to scare the blind idiots off the bicycle path at East Coast. You should see some of them jump off the path to the side thinking a big lorry is horning them from the rear heheh..
It should do the trick for your fun too...plus it is recyclable. the horn with the bottle is about $30. You can buy a cheap bike pump or use a petrol pump to fill it up I gues. A pumped up bottle can last quite a few blast ( about 40-50). If you have a hand pump you can recharge it all night