Extract unique values on each column separately

Sub RemoveDups()
    Dim wrkSht As Worksheet    Dim lLastCol As Long    Dim lLastRow As Long    Dim i As Long
    'Work through each sheet in the workbook.    For Each wrkSht In ThisWorkbook.Worksheets
        'Find the last column on the sheet.        lLastCol = LastCell(wrkSht).Column
        'Work through each column on the sheet.        For i = 1 To lLastCol
            'Find the last row for each column.            lLastRow = LastCell(wrkSht, i).Row
            'Remove the duplicates.            With wrkSht                .Range(.Cells(1, i), .Cells(lLastRow, i)).RemoveDuplicates Columns:=1, Header:=xlNo            End With        Next i
    Next wrkSht

End Sub

'This function will return a reference to the last cell in either the sheet, or specified column on the sheet.
Public Function LastCell(wrkSht As Worksheet, Optional Col As Long = 0) As Range
    Dim lLastCol As Long, lLastRow As Long
    On Error Resume Next
    With wrkSht        If Col = 0 Then            lLastCol = .Cells.Find("*", , , , xlByColumns, xlPrevious).Column            lLastRow = .Cells.Find("*", , , , xlByRows, xlPrevious).Row        Else            lLastCol = .Cells.Find("*", , , , xlByColumns, xlPrevious).Column            lLastRow = .Columns(Col).Find("*", , , , xlByColumns, xlPrevious).Row        End If
        If lLastCol = 0 Then lLastCol = 1        If lLastRow = 0 Then lLastRow = 1
        Set LastCell = wrkSht.Cells(lLastRow, lLastCol)    End With    On Error GoTo 0

End Function