This is a box I wired using the method Kevin was talking about.
Dallas
it takes getting accustom to but by driving the guide curve around with triball and then pressing "P" where you want points you can drag the triBall around in a plain otherwise the points jump around and attache to what ever. once you get the basic points, use more then you think you will need, you can go back and edit the guide curves to eliminate interference with other wires/hoses.