Any experience with oak cubes?

They work just fine. I've got to little dishes of cubes that have been soaking in Jim Beam for about 2 months now. One of these days I'll finally brew the Ceuriux clone I have here...

 

i soaked some in makers mark...i think for ~5 days. and then i dumped everything into the beer. i've only got the one experience with it, so thats how i did it. i'd heard from others that the alcohol soaks up more of the oak than the oak soaks up the alcohol so if in doubt just dump it all in. turned out great for me. i want to say i used 2 oz. of oak and 8oz of bourbon...could have used more bourbon but it was really just a nice amount.

 

I have used them several times. The best use was with a Bourbon Barrel Ale from Midwest. I soaked them in Eagle Rare Bourbon for a few weeks, them added them to the secondary where the batch stayed for 6 months. It worked very nicely. A recent cherry oatmeal stout didn't work as well. The oak seemed to impart a slightly disagreeable flavor, but it's hard to isolate that to the oak.