What exactly doesn't work with RemoveAllViews ?
I have modified your CleanPanel routine like this:
Sub CleanPanel
Log(Panel1.NumberOfViews)
Panel1.RemoveAllViews
Log(Panel1.NumberOfViews)
End Sub
With the two Logs you'll see that the number views is 12 before Panel1.RemoveAllViews and 0 after.
So RemoveAllViews works as expected.