I use 22oz'ers. Make about 300cc/ml sterilant. I use the percarbonate-type. Dissolve 1/4 tsp powder in the 300 cc warm(33 sec on m'wave). Pour into as many bottles as you think can be washed with soln.(solution). I do 5,6 ,whatever, at a time. Could do more, I suppose. No hurry.
Remember, bottles should already be rinsed after use, to remove big crud. No need to be paranoid now, as we're dissolving only a few microbes, not H7N9. Btw, if you get this stuff in your gloves, it will remove a thin layer of skin, no matter what the mfgr. says.
You may drain now or later, it's your nickel, but I'd leave enough in bottle to wet the tissue. The longer you leave it, within reason, the better it sterilizes. After a while, tho, it decomposes to oxygen and potassium phosphate. No rinse, remember?
I have previously cut off the top one inch of 1gal poly water jugs, with a snap-type(not threaded) cap. Hmm, never tried threaded type. Save the caps. Take a Kleenex type tissue, fold it over on itself into fourths, place it over the bottle, put on the poly top(with cap). It will fit snugly enough to stay put unless disturbed. You should wet the tissue with sterilant (from the bottle) now, to be sure IT is cleansed. This causes it to take the shape of the bottle neck, making a nice filter, when dry, for any air that might get in due to temp changes.
I have NEVER seen the tissue (or cotton) dissolved by the soln., so I just put the bottles aside until time to fill. If the wet tissue bothers you, you can take the snap-cap off(leave the ring, pull it down-it will hold the tissue in place, until it dries).
To bottle, you merely remove the tissue(now, it's stiff and in the shape of the bottle neck), but keep it clean in case you want to re-cover bottle to add inert gas atmosphere. Yes, they, tissues, can be reused.
I have NEVER had a contamination problem with new Kleenex out of the box, sterilized or not. Later!