I use a centerline car to dry the rail and a CMX car from Tony's to apply the 91% IsoAlcohol.
Now that I am having major ops sessions, I find I need to clean once per month. This is a large layout too.....
I wouldn't do the wahl clipper oil if you have a helix or heavy grades. Anything that makes the rail slippery will kill pulling power.
Also, be very careful of goo gone. I use to use it and after a while it got the rails sticky.
I started using IsoAlcohol and it works great and evaporates away!