There is something I don't understand: If you pretend do have a lot of customers (to feed illegal income into pretend purchases), why not also pretend to have a lot of employees? At least they don't need to be present, since this seems to be what make people suspicious.
I'm just guessing, but if someone does decide to investigate your business I assume they'll start by checking the people in it. If they find you've faked employment records then the gig will be up pretty quickly. Employing people keeps the facade up in the same way as actually serving food and drinks.
I suppose if your "other" side of the business has people working for it, then it's not going to change the financials much to have them on the books of the restaurant.
