I think there may also be misunderstandings because there may be various reasons to experience social anxiety, and different expectations when it comes to dealing with it.
A shy extrovert wanting to have more social interactions but having difficulties/fears/past traumatizing experiences will most likely not have the same reasons to have social anxiety, and not the same expectations for a life without this anxiety, as an introvert who gets social anxiety because they are forced by everyday life to socialize against their wish.
Plus the reason behind that problem may modify how to deal with it.
For the clothes issue, for example, clothing differently helped me, but only, I think, because two aspects were there: I loved the clothes I wore (I was not doing it to look different from mainstream (not either to look similar to a smaller group), but to look as I wished to look like), and I've never be searching for the approval of others. Dressing different was helpful in the sense that it was already screening out any person judging solely on exterior factors (because no matter how weird I could dress, it was still way less weird than how weird I am inside. What the point in keeping around me people that would already be put off by my clothes? Almost zero chances they would like me anyway). I was then left to deal with the persons the most likely to have some tolerance toward my weirdness and thus, the less likely to give me social anxiety. Pretty much the same way than toxic butterflies are colorful to warn predators BEFORE they take a bite -> it's good for both parties.
Also, if I had been forced, or forced myself, into more social interactions I would either be an hermit, or dead, by now. Although it may be a good advice for some, I think it's a very dangerous thing to say as a general advice.