My highest encounters have been 234k. 1/30k doesn't mean you WILL get a shiny in 30k encounters, it means there is a 1/30k chance for the encounter to be shiny. Like a 30k sided dice that rolls every time and only one side means shiny. It could take you 1 encounter, or 100, or 100k.
And especially if you're single hunting it's going to take a lot of time.