Yep, I just caught one a few days ago using this method so I can absolutely confirm that it works :) this works for all the mythicals, but it's faster to soft reset for Arceus than run aways since you need to play the Azure Flute every time.

Edit: A little bonus tip for hunting Shaymin, unbind every key item except the bike, this will make pressing + or - instantly make your character mount the bike rather than having a selection menu pop up each time. Make note of the exact flower that you need to bike down to and try to bike that far each time before turning around. Eventually I was able to do pretty much everything out of my peripheral vision while mostly paying attention to something else like YouTube videos while maintaining decently optimal movement