what product to use?

Wikipedia article says this...

Some newer dishwashers allow the use of "all in one" tablets (which include an amount of salt along with detergent and a rinse agent) instead of using separate salt and rinse aid, but dishwasher salt must still be added to the salt compartment in very hard water areas.

However, best results are achieved by using separate salt, rinse aid and detergent rather than using the combined "all in one" detergents with these included.

Incorrect use of "all in one" tablets/detergents may not be covered under the dishwasher's warranty; it is advisable to check the instruction book when using these types of tablets/detergents.

Peccavi
March 2010

Salt - Good quality rinse aid - good quality powder detergent - avoid the multi-tabs.

Purely personal opinion.

A cleaning tablet a couple of times a year may help - not sure though.

Wilipedia has an article on dishwashers.

Peccavi
March 2010