>>2765417This is the type of plastic champagne "cork" with wire to hold it in place I use, it's really strong, never had one fail ever.
Plastic can be reused so I don't have that many of them but wire can't so I buy them in batches of 200, this one is almost new.
>>2765420>bottles are an issueYou can buy champagne bottles rated for up to 6 bar in most wine making stores for pretty cheap, I got mine for a bit under 1$ per one in a wholesale store.
I wouldn't risk it myself with normal bottles, too much cleanup if one fails and you can injure yourself.