I must have millions of these to share.
Of course you really don't want these onions,
you really don't but you probably already have some in your possession,
they are wild! Wild onions that is!
They are everywhere in our landscape and gardens. From the garden beds to the lawn where ever you look you will find wild onions. Perhaps their presence is most notable when I mow the yard and their pungent scent emanates across the breeze mixing with the smell of freshly cut grass. To me the smell is actually pleasant and reminiscent of spring and summer. The truth is I don't mind them in the yard once the fescue starts growing, you never even notice them, but in garden beds that's another matter.

As for other methods boiling water works great if you have enough of it. I've tried vinegar and while it does make the lawn smell like a tasty salad its results were not as stupendous. Multiple applications are required but the plants eventually succumb. You could go to the nuclear option and try certain unnamed weed killers (or everything killers) but I avoid that route for the simple reason that I don't want too many chemicals to be released in our environment. Broadleaf herbicides are effective but you have to be careful not to accidentally spray anything that you don't want dead. The same goes for the vinegar as it is a non-selective herbicide as well.
In a way cool season weeds can be attractive. Just look at my clever fuss free arrangement of henbit and onions. It's almost like an ornamental grass rising above a sea of sprawling ground cover flowers.
Of course you could eat your way out of the problem, but you had better like onions. You had better REALLY like onions!