You could try this code....

Sub Tag_Strikethroughs()
  Dim aRng As Range
  Set aRng = ActiveDocument.Range
  With aRng.Find
    .ClearFormatting
    .Replacement.ClearFormatting
    .Font.StrikeThrough = True
    .Text = ""
    Do While .Execute = True
      aRng.InsertBefore "{"
      aRng.InsertAfter "}"
      aRng.Characters.Last.Font.StrikeThrough = False
      aRng.Start = aRng.End
      aRng.End = ActiveDocument.Range.End
    Loop
  End With
End Sub