Washing Machine Descaler I Need To Clean My Washing Machine?

I need to clean my washing machine? - washing machine descaler

Hello
I use a water softener in my washing machine, but I recently always black stains on the clothes, when to leave them.
Is there something I can use to clean? How about a dishwasher, run it with a vacuum cleaner to get rid of them no accumulation.

Comments?
Thanx