We use Canola, and on occasion Corn oil, the one time we used Coconut oil, people were bringing the corn back that it was bad so sorry to say no coconut oil ever again here!
Not sure what type Canola you guys have used, but I use Great Western Canola Popping oil, NEVER have has a 'Fish smell" it never gets "greasy", and even if kept several days is still fine?
Corn oil was OK, gives a slightly sweeter taste to the corn.
We pop with Flavacol, you can't get "Theatre Popcorn" w/o it! and to just add salt after you pop is totally not the same... would be as bad as microwave popcorn that tastes like paper! (only salty)
Mind you we don't add as much as they say to use, it's way too salty that way, in our 20 Oz popper one plastic teaspoon is plenty!
And we are using Luanna Buttery Topping.
Tony.