I havent gotten to use range cubes yet, most of the local farms buy'em all up before i can get to them. But i did sour some millet, wheat and cracked corn and used that this summer and it helped out alot.
here is an idea for you. take the range cubes and put them in a five gallon bucket. take some chicken livers (a couple of tubs) and put them in the blender and puree them. then put them in the bucket as well with enough water to cover the range cubes. let it sit overnight and then take this out and chum with it. i have caught some nice cats this way. you can also use chicken or beef blood, let the cubes soak them up and then let it dry out. then pull it out and break it up into about 2 inch pieces and use this for chum. works well either way.