I've got a handful of bottles I'd like to re-use, which have some serious
stains on the inside. The stains are from blueberry and pomegranate
(liqueurs, actually, not wine), and I can't seem to get a bottle-washer
(plastic cat-tail to scrub the insides of cylinders) to scrape away from
the inside. And my little water-jet attachment for my faucet doesn't peel
it away. I've got them soaking now in the presence of liquid soap, but
that's failed in the past. Aside from discarding these bottles entirely,
what else can I do to get them cleaned out?