I clean the cassette and chainrings with wet wipes. My chain has a quick link so it's easy to get off. Every couple of months or so I take it off and feed it into an empty one litre plastic mineral water bottle which into which I pour about a third of a litre of Jizer. This is a workshop degreaser which is water rinsable. Put the top on the bottle and shake it like crazy for a couple of minutes. Extract the chain ( you may have to cut the top off the bottle to get it out), give it a wipe on a J cloth, and put it into another bottle with a water/washing up liquid solution. Shake like crazy, empty, and then rinse in the bottle with clean water until there are absolutely no traces of bubbles from the washing up liquid.
Get the chain out and wipe it before sticking it in an oven for a couple of hours at about 70 degrees C. Put the dry chain on some old newspapers with the pins horizontal, and drip two tiny drops of lube onto each roller between the plates. When you have done that, wiggle each link back and forth to encourage the lube to penetrate. If you are feeling particularly virtuous, you can turn the chain over and repeat the process. I use Cross Country Finish Line Wet lube and apply it with a disposable plastic syringe with an 18g hypodermic needle. You only need 1-2 ml of oil for the entire chain. Finally, wipe the chain down, put it back on the bike, do a bit if Mickleing with a rag, and that's it.