No point raking the whole bush , typically if i get more than one nugget in a 20ft area that is covered in sticks and leaves raking it off to get max performance and coverage from your coil usually scores a extra couple of nugs usually it will give smaller bits the chance to signal , but if you cant get a nugget or two you will waste your day raking the bush and still find nothing . In my opinion.
I honestly have only raked a couple of patches as generally moving a few sticks and rocks will let the signals bleep and kicking the leaf litter aside with your boot will tell you if its a false or a target.
Trust me theres alot of nuggets that dont have any friends and raking will just burn daylight , it really depends on the situation.