The main reason not to put it in your pocket is that it'll pull your pants down uncomfortably. You don't want to grind it into a fine powder and breathe that in

The main reason not to put it in your pocket is that it'll pull your pants down uncomfortably. You don't want to grind it into a fine powder and breathe that in, or ingest it, but the toxicity is a bigger threat than the radioactivity.