Will the post office check the balloon (the inflated balloon, I blew it very small to prevent it from exploding)
Your package is very good, and the post office can send it, but it is estimated that it will leak if you send it thousands of kilometers. The advice upstairs is very good. Just find a frosted bottle and plug it with a rubber stopper, and then shut up with a candle oil seal. Also, don't forget to brush your teeth and chew gum before blowing, haha.