- Remove the case and battery if it is safe beforehand. This way you don't leave any place uncleaned, but you won't have to worry about destroying your phone's life source.
- Use a damp microfiber cloth. It won't spread excess moisture through your phone but it will also get rid of bacteria without using toxic chemicals. It's a simple and useful tool that can be used in just about any room of your home.
- A dry q-tip will help you reach into the crack in any buttons to get rid of some of the dust without messing with the keys.
Simply clean what you can get to and do it in a gentle manner and you will eliminate most of the germs and keep your electronic companion in good working condition.