integrated dishwasher

[Grayo]

If you're using three in one tablets then don't fill the machine with salt or rinse aid as this will cause the grittiness on your plates. The only way to clean spray arms is to take them off and force water through the wrong way but this can be time consuming. Finally, get some descaler, put it in the bottom of the machine and run the machine on a very hot cycle but with nothing in it and all these things should solve your cleaning problems.
You should also run your washing machine on a very hot wash with just descaler and no washing in it about every two to three months. This will get rid of the build up of old detergent which accumulates from using the same was cycle all the time. If it's not done the machine will begin to smell after a while.
I used to be a service Engineer for Hotpoint.