Re: Favorite penetrating oil that DOESN'T STINK!
Kroil, PB blaster, or liquid wrench. All 3 work pretty well if given enough time to stink up the joint.
Heat should be used as a last resort. Another thing you can try is having a welder come out and weld a new nut onto the one that you will probably round off. Sometimes the heat from the welding is almost enough to break it free. Works reall well, but I wouldn't re-use the hardware.
Merit 25 # 764 "Audrey"