I used AirCon cleaner and all the other odour eliminator, but nothing stopping this annoying dirty smell. Is their any other way that I can manually clean the dirts or so?

I don't know if this relates to your problem but I tried all manner of cleaners to eliminate the musty smell from one of my Roomsters.  They all disguised the smell for a while but the pong always returned.

 

Then I changed the pollen filter. Bliss!