I use the dishwasher pods; love them. No muss or fuss. I can't recall offhand which brand I use, though.

For garbage disposals, I often grind up citrus peel or other things I like the scent of; I also spray Lysol in there every few weeks (after having put all the dishes away). The Lysol does seem to take care of the odor problem.

Thanks for the Minerva_Fest shout-out!