Like Muhammad Hassan and Rusev

Yeah, it works, pity WWE has a shitty timing to choose when they should pop up.
Remember when Bret Hart was anti-America(n)? That worked.

Yeah, they can work. Sometimes they can just get boring, though, because that's all they go on about. I think Rusev has turned out alright since he started his.

They work, because Americans eat it up, being wildly over-patriotic. When I went to see TNA, Daivari cut a promo along the lines of "your Manchester City tried to pay Kaka millions of pounds to come here, and even that couldn't tempt him to this country," and we were like "ah, haha, he's playing a character, bless him."

Whereas American crowds are all "HE SAID WHAT? USA! USA! USA! HAND ME MY SHOTGUN. I DON'T CARE IF THERE'S A MEXICAN AND A JAPANESE GUY IN THE RING, I'M CHANTING USA."

^
Worse: Christopher Daniels vs AJ Styles, USA Chants. Or when Jim Duggan shows up at the Royal Rumble matches, against 10+ american wrestlers.

they do, but they usually have a short shelf life in more modern eras

Yeah, it's kind of hard to market an Anti-American gimmick while trying to appeal to a global market. Mink's examples are pretty telling, I think.

However, with American crowds, especially southern America, they seem to work really well. Jack Swagger's initial face turn received much bigger pops than I would have expected, and I suspect Rusev's heat is a pretty major contributing factor to that.

Then they did nothing to go off Swagger's face turn

Because Swagger sucks