A Drop Will Do
Use an olive oil bottle to dispense your dish washing liquid. The way the top of the olive oil bottle is designed will only allow a drop or two to pour out at a time, instead of the steady stream that you get from the soap bottle.
This lets you get just enough to do the washing without all the waste. Depending on the color of the bottle or the color of the dishwashing liquid, though, you may need to label the bottle so there are no mistaken cooking accidents.