That said, the idea of getting a single ounce bottle of something any reasonable kitchen should already have (like vinegar) does feel pretty gross.
Don't people poach eggs? You need vinegar for that. Boil a pot of water, two capfuls of vinegar, crack 2 eggs into something like a 3/4 cup measure, turn heat off wait for water to stop aggressively boiling, lower the measuring cup of eggs so it partly submerges, tip it to empty the contents (you don't want to drop the eggs in from altitude), lid on the pot, set a timer for 5 or 6 minutes. Play around with the time. It'll take less time if you have a stove with residual heat: glass or coils. It'll take more time if you have gas or induction.
If you do it a bunch of times, you can figure out when they're done the way you like them just be jiggling the pot and seeing how the eggs move under water.
The fresher the egg the more it will hold together. If it flattens out on the bottom, oh well some eggs do that even with vinegar. You'll get over it.
Next start making homemade bread for your eggs. And now you'll be willing to pay $6 for really good eggs from chickens that eat insects. OK I'm carried away now...