Tell the tightwad that running the dw cycle empty, with a cup of white vinegar, instead of soap, once a week, should help prevent lime build up. Or, you could really have him on the road to poverty, by demanding a water softener. That would prevent lime from every becoming a problem.
I’d read from reliable sources that you should use a packet of unsweetened lemonaid Koolaid in an empty wash cycle to clean the minerals out of the dishwasher. I tried it and it worked great.