Washing machine maintenance

Black dust on a finished laundry recommended these days obliged me to know the reason and to clear the problem. Killed I yesterday, because It took me all day long yesterday to disassemble and clean thoroughly the long used washing machine. Though a special tool was required to loosen the basket center lock nut, did I it by my steady effort with a hummer after all.
Dusty and ugly inner basket and outer case made me hesitate at the beginning to proceed the next step, made I it through with strong mind.
This kind of washing machine should have some periodical maintenance service at least once a year, so I conclude.