Can I drain a dehumidifier pump into my dishwasher?
Some dishwashers will pump water even when not in a cycle (just poured a litre or so into mine to rinse it and it pumped automatically - the door was open so not a cycle. But it needs to be connected to the electrical supply.

However, I would not suggest that you do this - sort a proper drain for your dehumidifier. As you may end up with a stagnant smell from not cycling the dishwasher, however, it will normally have a cleaning cycle.