I try to clean my drive-train every week, but have found myself getting lazy. I do like to take it apart and do each piece separately. I have not done this in about 2 weeks (this Friday) and think I should do so maybe today. I also like to take the rear derailleur apart and really clean the wheels. I also use some rags to get into the front derailleur and clean it to a nice shine on the inside (like anyone can see it). I can get real anal when it come to cleaning the drive train on my bike. The chain itself I will soak in a degreaser for about an hour or so. Rinse it off in another solvent, then dry it off for 30 minutes. When I put it back on I use a rag and some drops of lube. I will let the drops (1 drop per link) set for about 30 seconds and then wipe the chain. Move to the next section and repeat till the whole chain is lubed.