The ink from the paper is the actual criminal. I put my shoes in a warm room, rather than using newspaper, and let them air out for half an hour without trees. Once they feel dampened but no longer too wet, I put trees in and let them rest. Way more effective and healthier than news prints.
Sounds logical. This just came into my mind after reading a shoe catalogue of Church's in which it was reccommended to dry shoes with newspapers. I wonder if anybody has ever conducted some research whether the ink penetrates into the leather (and beyond?) or not. Too bad I'm not a chemist!