I tried the 'add detergent to the pre-wash-cycle' part. While it seems to make sense, it also caused a lot more rust spots on cutlery. The detergent is just too aggressive that way.
the goal is to use the cheapest not the most expensive... my miele tablets were destroying my duralex picardie big time, so I now use the cheapest powder and if I feel like the stainless steel don't shine bright enough (maybe once a month) then I use one miele tablet...