Strike them hard, something like “sorry, you breached our trust in the most disrespectful of ways, so now you’re barred from conducting any sort of business in our country for 20 years, and that includes any shell companies you set up”.
In the words of my late mom; it’s better to be alone than to be alone together with someone.
First time I saw that sign I was baffled, as in most other countries I’ve been to it’s illegal for employees to use the same facilities as guests. Then I got a bit grossed out thinking of the fact that employees apparently need to be reminded to wash their hands.
Mmm, jam-filled doughnut-eater…