Drink the bottle till empty. Put empty bottle in recycle bin.
Take the cap. A stainless steel bolt and a large washer. Attached the cap to the washer. Peen over the edges of the cap around the washer which has the stainless steel bolt through it.
You now have a hand made choke knob that cost around $10.
Take the bike's choke knob off. Fit the one you have just made.