If the filter is clogged, clean the treatment tip by rinsing it under the tap. If the ring is dirty, let it soak in hot water with washing-up liquid for 5-10 minutes. You can use the cleaning brush to clean it. Make sure you clean the filter with the treatment tip upside down to rinse off any dirt left in the filter. Dry the treatment tip with a lint-free towel or let it air-dry.