Here’s a simple, quick, cheap and easy way to clean and deodorize the garbage disposal – use vinegar ice cubes.  Just freeze some vinegar in an ice cube tray, and then put a couple in the garbage disposal. 

Another option is to use some cut up lemon peel or orange rind.  That works too.  But I really like the vinegar ice cubes because they seem to clean the blades a bit better than lemon peel or orange rind.