Clear contents of last column with data

Hi all,

I am trying to change this code to clear the contents of the last column of my "Master sheet". I am having trouble indexing to the last column, however. I found this code online but it looks much more complicated than it needs to be. Is there any way to do this easier/change this code to fit my needs?

Right now, the letter of the column I want to delete pops up in a message box, but I'm not sure where to go from there. Any advice would be helpful and much appreciated!

Sub undoButton()

With Sheets("Master sheet")
    
    Dim LastColumn As Integer
    If WorksheetFunction.CountA(Cells) > 0 Then
        LastColumn = Cells.Find(What:="*", After:=[A1], _
        SearchOrder:=xlByColumns, _
        SearchDirection:=xlPrevious).Column
        theRep = Replace(Cells(1, LastColumn).Address(False, False), "1", "")
        MsgBox theRep
    End If
    
End With

End Sub

Thanks.