Making it impossible for them to operate a business in the US ought to be more than sufficient.
But if TikTok really is as useful to the Chinese government to be the threat that the politicians trying to ban it make it out to be, surely the Chinese government would be willing to eat those costs to keep it going here.
Without revenue in it, and influencers on it, only few would jump through the insane hoops to sideload an app nowadays.