Delete Row with string containing special character

I am trying to delete rows that contain text with a special character in column O. The text I am searching for contains PO# and will look something like this PO#B7605887-1, so I need it to be PO#* so it catches the text if it contains anything after the special character.

The code I created below is not working. What am I doing wrong?

Sub Delete_POnums()
    Dim k As Long 'PO#
           On Error GoTo 0

        With ThisWorkbook.Sheets("Call Data").Range("O:O")
                For k = .Cells(.Rows.Count, 1).End(xlUp).Row To 1 Step -1
                        With .Cells(k, 1)
                    If CStr(.Value) Like "PO" & Chr(35) & "*" Then .EntireRow.Delete Shift:=xlUp
                End With
            Next k
        End With

End Sub