i use Canadian Mist bottles. they're sorta flat and lay in the bottom of the cooler real well.

yes they come out "fairly" easy, sometimes I have to lay it on its top and press them out with my hand but they release well as soon as you do.

if you want you can give it a spray with pam but I found the ice would pop out before you are ready sometimes so I like the control of it having a "little" grip on the bucket.

I found anything deeper the 4" and the ice would freeze the top first then the bottom swells and with no where for it to go it deforms or splits the bucket.

I tried 5 gallon buckets but they don't flex enough to be able to pop the ice out unless you run a hose on it to make it release and when frozen the plastic bucket cracks and splits very easy.

I find what works best is a bin about 15"x15" or something close and not more then 6" high

I use the Ice Cream containers [1 gallon + pint] size. I fill them up about 1/2 way and let it freeze [~ 12 hours]. Sometimes I add more water to make bigger blocks.

I also sometimes keep a gallon milk container full of water in the "spare refrigerator" and use cold water to shorten the freezing time.
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