For several years I used a dry rub/pack/whatever... Long enough to realize how foolish it is. Mixing a brine is faster, easier, and more uniform everytime.
I started out dry rubbing because I liked the kippered better than cold smoked. My tastes changed and I discovered that my family also liked the lighter smoke/brine as well, so I switched.
I have done a VERY light dry rub and then let the pellicle form, then smoke, but it wasn't the same as the brine.
Most folks marinate fish and seafood far too long, when cooking or smoking.
Ed