If you suspect Nitro to become "shock sensitive" you should dilute methanol to it and destroy as official department has instructed. This is how I read the user booklet which comes with Nitro.

I even add some oil to the mixture and ...

There is a possible danger in Nitro. Mixed with Alkalines makes Nitro some sort of explosive.

I once mixed 2 litres Nitro with 2 litres AeroSave in 10 litre can and shaked. It become green so the yellow "marker product" did react correctly because AeroSave contains rust inhibitor which is some sort of alkaline.