Look here.
http://www.handlaidtrack.com/forums/viewtopic.php?f=4&t=809
"DCC friendly" usually refers to how close the backs of the point closier rails are when open, to the backs of any wheels (flanges) going through the turnout or points (riding on the stock rails) and causing a short as the equipment passes through. You will have the same wiring to do for a DC system or a DCC system. (two rail track)
If you can't find any good information that you are looking for, draw a BIG diagram of your doubleslip and show each rail as it is either connected to something else or insulated. Draw it in a neutral configuration, that is, inbetween being thrown one way or the other. Make a couple of copies that you can draw on, then just fiddle with it. You might also want to think "crossing" for some wiring help. Chances are you are going to wind up using some relays and possibly a diode matrix to control the relays, through toggle switches.
As to the reversing loop, don't wire it into the doubleslip. Make the doubleslip as one block and the reversing loop as a separate block. I think you may have a better chance of understanding it that way.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Everybody treats wiring a double slip as if it were some arcane experiment in Boolean algebra. Actually, it is exactly the same as wiring two ordinary turnouts laid with their points almost in contact.
If the acute-angle frogs are hot, they must be wired to the switch thrower (machine or electrical switch) contacts for the device that moves all four points at the far end of the double slip. If they are electrically dead, no problem.
Now, draw a line from one acute-angle frog point to the other. Assuming you have put isolating gaps in the frog approach rails, and that your points are electrically dead when open, everything to one side of that line (obtuse-angle frog and both curved rails) is a single electrical unit and can be powered through a single feeder. If your points AREN'T dead, make sure that the acute-angle frog gaps are beyond the sharp ends of the points.
I have built a fair number of double slips over the last forty years, without any of them ever giving me any problems. They aren't as complicated as they appear at first glance.
Chuck (modeling Central Japan in September, 1964)
Go to Fastracks.com website and log onto their forums. Somewhere in there you will find a diagram to wire double slip swithes. They also make a jig to make those turnouts. Wath the video if you choose to.
Jules