The solution is indeed great, but as I stated in my question it will only work if you know what to delete and what to keep ! in my case the customers are writing the data through ACF fields and now then when they delete flexi field the data keep showing not only showing but in a very very weird way I have flexi field where people can write branches of there business some of the branches are already listed so I used the post object field to retrieve and put a conditional field that user may click not on list so he can write in text box, then I used the loop function on front end to display all the results now the problem is when user delete one of the entry it remains there, but being deleted it also over writes the manual hand entry !! because the association of the key become same, its like it do delete the associated key but not from db !