Tell us about yourself!
I can recall a "home science project" book I checked out from the library maybe 20 years ago that had a glass cutting project. You scored the bottle with a glass cutter, then used the "nichrome" wire from a toaster (plugged in to heat the wire) to cut it. I never tried it, but I'd imagine it would be pretty fast. I've never thought of this method (soldering iron). You must have tons of patience to do it this way.