Yes, you're absolutely right about removing the spark plugs being the best method. It also shows which cylinder actually has fluid in it as well. But if you're out and about without a spark plug wrench, you may not have that option and you definitely don't want to crank the starter motor!
By the way, I went with the Pingel petcock.
Instead, put your bike in 2nd or 3rd gear, and push it forward a little. If you're hydrolocked you will see about a cup of gas get safely pushed out of your tailpipe.
Actually I would push the bike backward to clear the cylinders, pushing it forward is doing the same as the starter trying to turn the motor. If there is gas in the cylinder you will end up with gas in the muffler. Maybe not a good idea.
It would be safer to pull the plugs and push it forward or use the starter to spin the motor (if all of the sparkplugs are out).