I do recommend using oil or grease on the bolt threads.  Stainless nuts have a problem with deforming under the right kind of pressure and locking up.  It is rare but it happens.  Someone told me this cure, so I pass it on to you.  The secret to preventing this is to lubricate the screw threads both before and after tightening or loosening.  If you are aware of it starting to seize, stop immediately and lubricate the threads.  If you try to force it, it will totally lock up and has to be cut off.  If you catch it before it locks, and lubricate it,  usually you can work the nut back and forth gently and many times the nut will loosen and be usable.