Use 2 liter pop bottles for the freezer. Contrary to what might make sense... fill them FULL, then freeze. (Yes, I know that water expands ~9% when it freezes) So far <knock on wood) I have not had any bottles split and none have even fazed the cap - frankly, most don't even noticeably bulge. These bottles are relatively heavy gauge PET and are designed for a modest bit of pressure from the carbonation. This is far superior to milk jugs and the water is potable when the bottle thaws.

We don't drink much pop, but friends save the bottles for us. I do a light rinse with tap water, leave the caps off, and then when I have enough to make it worth my while, I "process" a batch.

Sorta like washing dishes - wash, rinse, sanitize, air dry. Sink with hot water + Dawn, sink with clear water (refreshed as required), one bottle half full of water + plain bleach. As a bottle is washed and rinsed, the sanitizer bottle contents are transferred; shake it up to coat inside of bottle with sanitizer (clean cap kept on counter for that) and set it down. Now-empty sanitizer bottle slung out vigorously and leaned up to air dry. Wash next bottle, etc. I use a pretty hefty mix of bleach-to-water - no harm. Re-rinse with tap water if it bothers you, but... there's no need.

Last are caps and sometimes a dish scrub brush helps in the threads if you were not paying attention when you initially rinsed the bottles. Set out a small plastic container (e.g. margarine tub) and as the caps come out of the rinse water, drop them in. Wait one minute after the last cap is set in, then remove all and set aside to dry. Go slosh the "spent" sanitizer in/around your shower...

In theory the "pressurized" frozen water will have a lowered phase change temperature, but at the pressures we're talking - there's no change, despite internet myth. It still freezes at or around 32 deg F.

These don't freeze frothy - they're like lethal weapons when frozen <grin>. Think bowling pins.

Seriously, ditch milk jugs - nasty - use plastic PET pop bottles instead.