I have found the best way to clean the washable filter is under the garden hose. I use a nozzle that creates a moderate pressure spray/mist. It is much more effective than rinsing it under a running tap and doesn’t appear to damage the filter.
My recommendation is to use compressed air, and sometimes wash the filter gently with just warm water - not hot. Compresseid air: after 5 cleaning cycles, water after 50 cycles.
I was able to buy the cleaning kit (1 main brush, 3 side brushes, 3 filters) at a very reasonable price for about 35 USD.