Heeheee, as you can see, everyone has their own way. The one thing that CAN NOT
be debated is that clean water is the best thing you can do for the health of any of your finned ones. :)
The question was CAN you use Stresscoat. The answer STILL is yes. It will not harm your fish, it might or might not help them, either, but if it makes you feel better to try it - no harm will come of it. I've personally never had a problem with any of the above mentioned things clogging my filter, but I have a HOB, and usually take the clean water tactic first.
Melafix is actually a natural remedy made from oils of the Melaleuca tree (Pimafix uses Teatree). As far as HUMANS, I use these oils in home-remedies all of the time and can attest that they're wonderful. I'm not so sure how much good they do in fish, lol, but I always feel far more comfortable using these treatments because I understand the ingredients - as opposed to anything else.
As I said, I've used Melaleuca in the water to treat fins before - as a preventative and to help speed healing. I'm not sure if it had any effect, or if it was the clean water and stress-free environment that did it, but his fin was nipped to the nub, and healed back in record time - lol, I didn't scoop the fish out and dump it on him, can't recommend that tactic!!! ;)
It also can't hurt to keep the lighting low - fish don't need the tank lighting, and it can add to their stress, so keeping things dim might help them settle in and heal up more quickly.