And then just wait

Or thread a string through one and put it in the cap of a soda and cut off the excess string. That way when when your friend opens the soda the mento will fall on its own. Boom

freezing them wouldnt work, because when you get the Mentos wet, their pitted candy surface starts to dissolve. And without a surface that's covered with thousands of little pits, there's nowhere for the carbon dioxide to go, which is what creates the fizz. Instead, you just have a gross soda.

Also pretty sure it only works with diet coke because of the artifical sweeteners. Yeah? It's too late for me to do Internet research

Hah, jokes on whoever does this to me, I'll drink the soda before the ice melts