How about a pump sprayer for the soapy water, Glen? Mine gets 2m. or so above my head if I keep it pumped up.
It also holds 8 liters which could probably spray your whole tree in one go. With the pressurized spray it might get a little ways into the leaf axils, too.
I'd also spray the dead leaves that you mulched up with the soapy water, to kill off any larvae that might have survived the mulching process. It might help with the smell, too.
I have found it helps a bit with removing the sooty mold off the living leaves as well. I leave the soapy water on the plant for a little while, then rinse the whole thing with a sharp spray from the hose.