Delete All Rows Hidden By Autofilter

I'm wondering if anyone has a answer to the problem of deleting all the rows that are hidden by an autofilter. We currently have a spreadsheet used within the office that catalogues all applications received, and we want to select all the applications that are relevant to a certain month with the autofilter and use a macro to delete those that are irrelevant, before emailing the spreadsheet to a client. Manually deleting all irrelevant rows would be time-consuming.

The current code I have is:

With Worksheets("Sheet1")
If .AutoFilterMode Then
With .AutoFilter.Filters(1)
If .On Then
Else: Rows.Delete
End If
End With
Else:
End If
End With

The theory is that the code first selects the relevant worksheet, determines whether autofilters are on, selects data that is being covered by the autofilter, indentifies those that is being displayed and does nothing, and identifies those which are not displayed and deletes them - in theory!