Nope. I don't really own any formal wear and I've always kind of hated it. I don't think I would get a similar placebo effect to you, because I have very different associations with it. I think, for me, it would be uncomfortable, awkward, and distracting. That's how I felt about it the one job I did have to dress up for (and my coworkers gave me crap for just how barely dressed up I was... just barely inside the lines of the dress code).

Sometimes I'll go to a coworking space or a cafe when I need that sort of kick in the butt change of environment. But for the most part, I need as comfortable and familiar an environment as possible in order to get in the zone.

More than 5 minutes a day thought on clothing and what others wear show that one has idle time to spare- and can not use that for something really productive.

It might be different for sales, but for problem-solving, stability and familiarity in the environment (clothing) are most important.