Did a 100% wheat malt beer this fall. One hour protein rest and 2 lbs of rice hulls for 10 gallons. Did not stick!Some day if I am feeling adventuresome, maybe a 100 rye mash. A small test batch would be done first to see if it would work. Would do a long Beta Glucan rest first.
I had a buddy who once did a 100% wheat beer. It was pretty darn boring.