What is the best way to clean a computer, keyboard, external hard drive?
Compressed air! If you don’t want to use the cans, you can use something like a high-powered tire pump (the name is escaping me, but it constantly blows out air at a higher pressure). It’ll get all the dust and bits out of the keyboard, take your computer outside with the side off and dust in all around the fans until no more dust blows out, and you can clean the EHD with it too.