Well, first let's talk about the air sickness bags. They are not really decreased, it is just how fleet servicing work sometime. When a plane arrives a major base of the airline it get fully serviced, that includes placing in flight magazines and air sickness bags, etc. This happens also when the plane has an enough ground time without passengers onboard. As the plane proceeds with its schedule for that day (5, 6 legs?) the supply of bags on seats goes less as the plane does not gets fully serviced in every stop usually due to short ground times.
Now, let's talk about what to do if you are one of the unlucky people who have a strong urge to vomit but no air sickness bag available?
- Run to the nearest toilet, that's the best option of course.
- If toilet is busy, vomit next to the toilet. In many airplanes the area next to toilets are not covered with carpets, instead they are covered with some plastic material. This will make the crime scene temporary as it can be wiped easily leaving no traces or smell.
- Can not run to the toilet? Do it where your legs should be or in the aisle. Why? Because these places are accessible and can be wiped a little or covered with a blanket till the end of the flight to avoid the strong smell, DO NOT do it on the side if you are on a window seat, no one can access there and the smell will be there for the remaining of the flight. Do not vomit on the seat pocket as well.
Now, if you did it anywhere other than the toilet, ask the flight attendants to bring you two blankets. Use the first to wipe it, the second to cover it (if they didn't do it themselves). The clever tip from a senior cabin crew member is: ask for a coffee bag! The same one they use to brew coffee onboard, cut the bag open and just cover the vomit with coffee before putting the blanket. I can assure you the smell will be 90% less, which means less embarrassment for you and more comfort for all people around.
Remember: There is always a stash of those somewhere in the plane, you can always ask to have one from cabin crew.