Using metaphors is tricky.

I pick up at least one piece of trash/litter every time I'm out and about (I no longer drive) but I draw the line at tissues/wipes. So far so good.

However, tissues and wipes are something of an exception because their job is to clean up "mess" and as the author points out we don't know what that mess might be.

Other forms of trash/litter are far less ambiguous eg. Soda/drink can or unstained paper bag, and I pick those up without a second thought.

So that metaphor is itself ambiguous and I'm left confused about the author's intent.