This is a fun fencing party trick. While I’ve not worried about the chilling step, having a good bottle of champagne with the heavier weight glass and good seams is a must to get a good cut at the champagne bottle.
The pressure in the bottle blows out the neck and any shards of glass, giving you a nice clean pour.
You can use any good ceremonial sword for this, or get a specially made “Champagne Saber” which is shorter than a normal sword and has a more weighted blade.
Read Alton Brown’s full instructions at AltonBrown.com