Don't just heat it, get it up to a good rolling boil to totally kill and baddies in the grain. Any malt that can be steeped could theoretically be done as a tea. You could see a small fermentation restart though. Crystal probably has some small amount of fermentable in it.
Kegged: Mr. Hyde's Dark Hearted English Ale, Pumpkin Lager, Bro'Hemian Pilsner
Resting: Stinky Pete's Midnight Wheat
No-Chill: Graham's Cracker Brown Ale
Bottled: Lowland Oatmeal Porter, Adieu Travail Belgian Sour, Golden Blossom Braggot