Sub Clean_and_Trim_Cells()
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
Dim s As String
For Each c In ActiveSheet.UsedRange
s = c.Value
If Trim(Application.Clean(s)) <> s Then
s = Trim(Application.Clean(s))
c.Value = s
End If
Next
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
End Sub