Efficient alternative:
Sub Delete_Columns()

    Dim rngFind As Range, rngDel As Range, sAdress As String

    With Worksheets("Accruals (2)").Range("A16:Z16")
        Set rngFind = .Find("FALSE")
        If Not rngFind Is Nothing Then
            sAdress = rngFind.Address
            Do
                If rngDel Is Nothing Then
                    Set rngDel = rngFind
                Else
                    Set rngDel = Application.Union(rngDel, rngFind)
                End If
                Set rngFind = .FindNext(rngFind)
            Loop While rngFind.Address <> sAdress
        End If
        If Not rngDel Is Nothing Then rngDel.EntireColumn.Delete
    End With
    
    Set rngFind = Nothing
    Set rngDel = Nothing
    
End Sub