Clean? I've never done it and probably should think about doing so. I don't think, unless you have REALLY messy remote habits, that your problem is with cleanliness. I assume you've replaced your batteries. If so and your remote still is unresponsive -- yes, indeed you can replace remotes and they can be programmed to your service and television model. We've done it a couple of times over the past 15 years with different TV's. Sometimes the remotes just become unworkable (for the lack of a better word). You should consider getting a new remote; read your manual and re-program your TV and service. It's done all the time -- good luck!

If you've already replaced the batteries, try using some peroxide on a toothbrush. Don't soak the brush, just make it damp then rub around the buttons. This should help loosen any surface dirt.

Don't wet it use compressed air to loosen and then use a dry toothbrush--repeat if necessary. Then maintain it by using the air every once in a while

I occasionally clean all my "electronics" including phones, remotes,lightswitches, etc. by dabbing on some rubbing alcohol with a Q-tip. Keeps things from getting "gunky".

Absolutely rubbing alcohol. What every applicator you use, q-tip or paper towel make it just damp not wet with the alcohol. Alcohol will remove the gunk, kill the germs and evaporate fairly quickly.

Deep cleaning instructions, how to take it apart etc., may be found at How to Clean a Remote Control along with links to cleaning similar products.