I own a medical practice. We have 8 employees. I am the only Jew. I have a private office within the practice where I eat. The rest of the office space is common space for any employee to use. I work on Chol Hamoed. What is the best way to clean for Pesach?
Inform the staff that you will be cleaning the office from all food before Pesach.
Before Pesach, You must remove the Chometz and clean the kitchenware like coffee mugs and microwaves etc.
However, as long as you do not plan to use them over Pesach, they do not need to koshered for Pesach. But they should be locked up.
During Pesach: The best arrangement would be to set a policy in place where the workers May not bring any food over Pesach. You can arrange with a Jewish caterer to supply kosher for Pesach meals.
However, according to strict Halacha, the Goyim may bring their own Chometz in your premises, provided it is not being stored there. if the Goyim bring in their own Chometz into your office or prepare a coffee with milk which is not kosher for Pesach, this is not your problem, for this belongs to the Goyim. But in a case where there is an arrangement where you are responsible to supply lunch for your workers, then you may not allow them to bring in Chometz in the office on Pesach, even if it is their own Chometz.
Either way, you are not allowed to let them eat their Chometz on the table while you are eating there too, even if you are using a separate tablecloth. If they are eating on the table while you are not eating there, ensure that you clean the table very well after they eat their Chometz. You also must ensure that when they leave the premises they take all the Chometz with them. If they did not take the Chometz with them, then you should throw out the Chometz.
See Shulchan Aruch Admur Hazaken 447:3. 440: 3-6.