To sharpen blades, fill the disposal with Ice and 1 cup of vinegar. Run cold water and flip on the disposal.
To deodorize the disposal, take the lemon cut up and place in the sink. Flip on the cold water and turn on the disposal. Let the lemon (or lemon, grapefruit, orange) enter the disposal and continue running with the water until it clears. This should take care of any lingering smell in the disposal and helps freshen the drain. (Tip: Run this before an open house or party to freshen up the kitchen naturally)