Been around a few snowblower forums. have never heard of anyone applying lubricant to the inside of the discharge chute, however, many owners apply several good coats of automotive wax to this area and say it helps.
It's a little different story for me

I had never heard of putting anything in/on a discharge chute until this year while doing research before a new snowblower purchase.
There were lots of references to WD-40, silicone spray, even Pam non-stick cooking spray in many forums. Evidently, several products are marketed for that use. The Fluid Film happened to be one that was well thought of and since it was available at the John Deere, Ariens, Honda OPE dealer a few blocks from me, it seemed like a good choice. Maybe I can offer more information after a season's use.
One of the often commented on benefits of FF is the corrosion/rust resistance. Some users spray the entire machine to prevent rust. I did spray the chute, impeller, auger, and inlet scoop of my old unit, but I don't know if it will be of any value or not just yet.
Hey, for less than $10 a spray can, it seemed like it might be worth a try. It took very little for my use.
FWIW, in almost 35 years of using my 8 hp, 26" wide, MTD built 2 stage, I have never applied anything to the chute and I have never had a clogged/plugged chute.
*********
Interesting discussion, but my original question remains unanswered.
For those that use Fluid Film in the discharge chute:
1. How often do you apply it?
2. Do you apply it immediately prior to use, a day/week/month ahead?