I think this is one of those 'If it works, it works, if it doesn't, it doesn't' things
Out of curiosity, a couple of years ago I tried NPP on some JSB Heavies in a .177 HW100.
It made the accuracy worse.
But, some time later, I ended up with a .22 BSA Superten.
Lubing pellets for this improved accuracy and made cycling the action a lot smoother.
Now, I'll try it if there's an issue, otherwise I don't bother.