I'd worry about dish detergent in this heat. It might work, but it might really mess up the foliage. Maybe if you sprayed with that and then washed the daylights out of it with a garden hose. Maybe, repeat that a couple of days later?
We coastal folk, we're just not used to these temps (It was 107 deg here, day before yesterday) but I have an awful feeling we best get used to it.
