I guess the selcon is going to be helpful with the mysis or other non-marine foods you might feed – a good reason to have some on hand. But I would consider it a lot less necessary for the better whole foods you can find. Depending who you're feeding, you can even dose small amounts of selcon right to the water column, or perhaps into a pump for more dispersion if you're feeding corals.
I'd prefer something like "reef plankton" for whole, larger food items and something like fish eggs or even newly hatched brine shrimp for tiny mouths and corals. Mostly no supplementation necessary, and no mess for something like fish eggs.
BTW, I consider the "mess" from processed foods just to be coral food....so that's another angle to keep in mind.
IMO, too many folks are phobic of nutrients due to fears of algae. (May or may not be you...just sayin.) Algae can be a problem with or without dissolved nutrients in the tank – so there's quite a bit more to the story if you have an algae problem. Feeding your animals right is definitely NOT the problem.