It’s a good idea to clean your watch every 2 to 3 months to maintain its appearance and keep it in good working order.
Make sure the crown is fully pushed against the case, and the seals have been changed or tested at a Thomas Earnshaw Official Service Centre within the last 12 months. Only then it is safe to be washed in slightly soapy water, using a soft brush. Rinse and dry with a dry soft cloth after washing.
If you have any doubts about the water-resistance of your watch, simply clean it with a soft brush.