I have one that I bought from a garage sale years ago for $2. I didn't think it would last this long because so much of it is plastic, but it has and works great.
I just checked the original container against other plastic storage containers I have and the Chinese restaurant quart soup containers would fit perfectly in the shaver. You would just fill it no more than a few inches high before freezing. We used to occasionally get hot and sour soup from our favorite Chinese restaurant in Michigan in these containers and I've used them over and over. They're like deli containers but thicker plastic and much sturdier. Here's a photo: http://tinyurl.com/989fglr
I make a simple syrup from sugar and water and add KoolAid to use for snowcones.