I tried to make dog biscuits with my spent grains, but it was not a big success ;-) I read that we could make more beer reusing the grain again. I liked the idea of making a lighter version of the beer this way.

If I make an all grain stout, what can I expect to be able to do by reusing the grain? 

1- Can I only add some more 2-row to a new mash to raise the OG, letting the flavor and color coming from the crystal and chocolat malt that was already mashed once? I believe I would get something close to an amber beer.  

2- Or is it possible to just batch sparge again and start from there?

Anyone has tried this?