I thought I would chime in here about what I do know about using cob bedding. I happen to use shavings because they do a good job and are easy to obtain BUT I have a good friend with a farm and small flock of chickens that uses cob. He also hatches eggs on occasion and he uses ground cob in his brooders.
Although Delaware is a BIG corn state ground cob is not that common. Because Leonard has a lot of acreage in feed corn, does his own harvesting, and has a cob grinder, I am sure that is why he uses it.
I guess others will also post and you will probably get a variety of good opinions.
Good Luck
CDA