Both will do. 300ml Elaine spray can be checked, and 100ml Elaine spray can be taken directly on the plane. According to the regulations of the Civil Aviation Administration, the spray not exceeding 100ml can be carried on the plane as carry-on baggage, but it needs to be checked as long as it exceeds 100ml. If you are still worried that you will be detained after the security check, you can check 100ml hydrating spray with your luggage on the plane, or you can repackage it in advance in case of emergency. 300ml Elaine spray exceeds the capacity limit 100ml, so it must be checked by train, high-speed rail and plane.
When you need to travel, if you need to carry a spray, it is not recommended to bring a 300ml large-capacity hydrating spray. First of all, because the bottle is big, it will be inconvenient to carry, and secondly, it will be checked, which will add a lot of weight to short-term travel. If you really want to carry it, it is recommended to carry a small amount of hydrating spray or repackage it when traveling.