I think you are seeing notices about people brewing something like Eisbock, not something like ice stabilized beer (eg Labatte Ice).
If you want to do the later, IIRC you are trying to freeze about 2% of the water in the beer into tiny crystals which requires agitation during the freezing. Compounds that cause beer staling are selectively removed in the ice crystals. This is a method of producing stable beer and nothing else. You will not be able to do this at home successfully and you would be much better off using filtration and fining instead.
You can read more about this in Principles of Brewing Science by George Fix and, I am quite sure, in the trade journals.