deleting fb search history?

[Kartikeya]

I want to delete the fb search history and i have tried going to activity log and then clearing the searches but even then same thing pop up in the search bar which i had searched earlier when i type even a single letter. this is ridiculous ! search history cannot be deleted ... it means that fb is using it to optimize our search ...clearing searches is just for false satisfaction and all the serch history lies with fb?? i want to delete it pls help....