Dishwasher Salt goes in the screw hole in the base of the machine - you fill it up with salt and it lasts for several weeks.
In the drop down door there's a chamber for rinse aid - you fill it up with rinse aid and it lasts for several weeks.
Also in the drop down door there's a chamber for detergent - you put the tablet or powder in the chamber and close the flap - during the washing cycle the flap is opened to release the detergent - a 3kg tub of detergent powder should last for several months.
From what you say I would guess you're putting the detergent into the salt place - but I just guess. The operator has absolute control over detergent - how much is put in for each specific wash.
