Ah, that stuff. I have never used it (either on electronic equipment or on rails). THe online reviews are positive (for its intended use).
If you read the info on their website
http://store.caig.com/s.nl/sc.2/category.188/.f it mentions that it doesn't harm plastic, so you could try it on rails with plastic ties). There is a Data Sheet PDF on that website which shows what ingredients are in this stuff (one proprietary of course).
I suppose it might work on rails. I wouldn't spray it though. I would either decant it from the spray or buy it in a non-aerosol liquid bottle. If it was me, I would then use it in one of the N scale wet pad cleaning car systems, running the car around the layout. I have a feeling that it will leave a moist residue on the rails (which IMO is not a good thing). You might test for that by spraying some Deoxit on a non-absorbent surface (piece of glass or metal) and see if an oily film remains after the solvent/cleaner evaporates.