As I mentioned earlier, the reasoning of knas was not my invention; it’s a Chasam Sofer and a Chazon Ish (the L”H, even though also machmir, disagrees on this point).
Mahara”m Schick apparently, as well.
http://www.hebrewbooks.org/pdfpager.aspx?req=1494&st=&pgnum=198
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