You’d still have to get in and out the countries, and go through authorities. Even if HK let’s you come in with a bag full of cash, you’d still have to get out of France. Last time I checked, customs don’t let people fly w/ cash.
But, you can act like a baller, and tell that the cash is for a take-it-or-leave-it deal, but the cash have to be squeaky clean, and you have to provide a ton of documents and stuff.