Hi Pepsi
When you take off the Air Con Cover you can see the Metal element that soaks up all the Room Vapour…
They spray a Neutraliser On the metal element. that sucks up all the bad Elements and moisture and it deodorises the exit pipe
God I hope you Understand what I mean.. I had to find out myself as my apartment in Salou Last year had it done and it cost ?90!!!
So I watched them do it and Its easy stuff! The Spray and liquid costs ?25!
If you need anymore help.. let me know see if I can get you a DIY instruction it is very simple once the cover is off!!
Regards
Anthony