along with the previously-mentioned lemon rinds (orange and lime rinds work, too

), try a somewhat profuse amount of baking soda along with some white vinegar.
flush the sink once the foam dissipates.
as for dishcloth odors, buy a few containers of those Palmolive disposible dish cloths, or buy a lot of bleach... i throw stinky washcloths away when they get an odor...