If you don’t want to waste your champagne, grab a can of shaving cream (the regular white foamy kind) and squirt enough to cover the stain completely. Wipe into the carpet (with aforementioned scrubby sponge), lifting up any excess cream. Your stain should disappear! We got the shaving cream tip from our neighborhood liquor-store guy when we were buying our delicious champagne. It works great…and is fun to use, if you don’t mind your carpeted room smelling like a barbershop for a bit.
More help with stains…