Think of it this way, if you had a cloth or napkin that Jesus used to wipe the sweat from his brow, would you use it to clean up the table? To wash dishes with? Or would His having contacted it make it "special"? Something dedicated as sacred is not then used for mundane purposes.
How more so with Mary, who had the most intimate contact with Jesus, providing his sustenace in utero.
SD
Sorry, I'd wash my dishes with it. He used it for his purpose and for it's purpose. So to should I. And I would for a reason. God created everything we see. Who cares if he touched a rag when he created the fibers that made it?! It isn't any more special than a rose bush. And it has no power, no authority and deserves no adoration. My Lord deserves the adoration. Not a lump of cloth. And wiping one's brow doesn't dedicate the usage as sacred. Oh, wait, I suppose you'd reverence yourself befor his discarded toilet paper too - or perhaps a bit of sacred fecal matter? Oh the horror.