Ther on-screen placeable must not be marked as 'Static', nor can it be an 'Environmental Object', otherwise, there's no way to manipulate it even via script.
If it IS a placeable that's not 'Static', you also need to ensure whether in creation or in the script that it is NOT flagged as 'plot'.
Once all these criteria are set, then the placeable can be removed permanently via the
DestroyObject()
command.