I have used it before. Has worked best freezing the chunks of tempered CB and then grating them with a Microplane. Start adding at ~95. Used at 1% of the total chocolate weight.
We only freeze it to grate it. So no, it does not throw off the temper.
Great info...I will try it out.
Mycryo is comparatively expensive. Cheebs' suggestion is a way to produce essentially the same product for significantly less money.
Why would you? I know some people do it to increase viscosity or shine, but those should be manipulated by the chocolate that you choose and your process - usually pure cocoa butter is more expensive than the couverture. Just curious.