To clean guinea pig poop, you need to have a plastic cup and spoon handy, which should always be kept in the cage. You can scoop the poop with the spoon into the cup and then empty the cup. In case the guinea pig poops in the house, you may need to use Lysol to clear the smell from your room.
get a cage with an open bottom, with a chicken wire- thing stopping the guinea pig from escaping, and keep it outside, with a place to keep it out of the rain. the poop will fall on the grass, and you won't even have to clean it up! we did this when we had one.