According to the perk's text, "crouching stops combat for a moment and forces distant opponents to search for a target".
Now... does that actually mean that, if your SW-perked character crouches, they re-enter stealth mode and their next attack is a sneak attack?
For instance..

I see an enemy archer in the distance. From stealth mode, I fire, breaking stealth and entering combat, meaning attack 1 is a "sneak attck" while attack 2 would be a normal attack. If I were to then crouch, does that mean that I am back in stealth mode (however brief) and that attack 3 would be a "sneak attack"?

What it does is that it kind of makes you invisible for a split second open entering sneak, this allows you to escape easier. but they would have to lose sight of you if you want to perform another sneak attack

trust me this perk is one of the more usefull ones

It means if you crouch all enemy's at a distance that detected you (eye open) would enter into the "I think I heard something state" (eye slightly open).

If there are shadows nearby or a solid object to hide behind you can get hidden pretty quickly. In the open in well lighted areas, it will just give you a half closed eye for a second.

That said, SW does make you invisible for a second when you first activate it, so if you are close to an opponent and are quick about it, you can tap in to sneak mode and land a quick dagger strike for the 15x sneak bonus, even in well lit areas. This is kinda cheap, since it was not the intended use of SW, at least not according to the perk description and does not really work with a bow because it takes too long to get off a shot. There is a very short interval between tapping into sneak and landing you attack if you want to trigger a free sneak attack.