Whirlpool DWF B10 washing dishes poorly

[JohnDB2009]

My friend has a built in Whirlpool DWF B10 dishwasher which works. but not well. Its problems are: 1) glasses end up milky probably because the water softener is not working (there is a large congealed lump of salt in the base), and 2) dishes are left a bit dirty (spray heads often blocked). I cannot see how to deal with the water softener issue (there seems to be no hard/soft water adjustment), and I regularly have to clean out the bits of food that get stuck in the rotating arms.

What should I do to fix these problems?

 

[cakeman]

The main problem here is that the dishwasher itself and all the pipework is probably full of gunk
run it for 3 hot washes with nothing in it , drop a couple of lids of bleach in the base each time too.
see where that take you

 

[Leccy758]

Scrape all plates etc before putting them in the machine, the bits will not be in the machine to clog it up then.