Beyond regular cleaning (as you would with any toilet), a yearly or half yearly inspection is advisable. Turn the power off (to stop the fan), open the toilet and look at the mesh cover over the fan.
The cover is removable on the Villa, so take it off and brush off any debris as required. With the cover off, look inside and visually inspect the fan blades and if needed, gently brush off any debris with a soft brush. On the Weekend, use a soft brush to remove debris from the mesh cover.
If you have a Villa, check the condition of the cables that operate the concealer screen and bucket rotation. Use an appropriate lubricating oil (the type suitable for bicycle gear and brake cables) if needed to ensure the cables run smoothly and are protected from corrosion.