Every major browser has handled Unicode adequately for many, many years now. (And your browser charset setting matters only for pages that don't declare the charset used, which is now rare, and violates the HTML standard.) It's flabbergasting that this forum is still limited to some 8-bit character set somewhere in the toolchain, and it's equally flabbergasting that more effort has gone into hackish workarounds than a proper fix.
Getting Unicode fixed once and for all would not only allow for Greek characters (and phonetic, and other foreign and symbol characters) to work, but emoji as well on any halfway recent OS.