Absolutely. My cure is salt/sugar based and you can add 0.25% of Cure #1 if you have fillets thick enough you think you will exceed the 4 hour window of safety. It's a dry cure that turns into a syrup after drawing out some liquid from the fish. After trimming the belly, those two fillets ↑↑ were just over a pound each, trout fillets are much smaller, so I get them to 145° in about 3 hours or in the winter I move them into a 180° oven to reach temp. Parts of my technique are embedded in older posts here, but this is the direct link to my fish curing
ARTICLE with many photos and some alternate smokers. I prefer the plastic wrap method, and my vintage Big Chief electric box smoker is the most reliable for me.