Well, I'd have to say that when I contact a recruiter, I specify exactly what I am looking for, as regards location, teaching hours/week, salary, other contractual payments and perquisites, contractual conditions of employment, public or private sector teaching, kindergarten or junior high school or senior high school or college or university. I insist on being provided with the contact details of employers wishing to hire me, and on communicating direct with such employers before considering a job offer seriously. I'd NEVER allow a recruiter to place me somewhere. Instead, I have the final say where I am bound for, and am NOT prepared to negotiate a teaching contract with a potential employer under any circumstances! If the overall employment package meets my demands, I might well be happy to accept it. But of course, I'd have googled the employer's name first to see if I could dig up any dirt. I would NEVER ask a potential employer for the e-mail addresses of his (or her) former or current foreign staff. I know that they are NOT to be trusted either, and what's one man's meat is another man's poison. Once I'd found a job tailor-made to my requirements, I'd insist on an electronic copy of the contract and its appendix, to be stamped by the employer first. I'd sign it, and scan it, before e-mailing it back to my new employer, and at the same time to my recruiter.
Summing up, recruiters can find job opportunities for foreigners, but thereafter filtering is necessary to separate the wheat from the chaff! Many Chinese recruiters would NOT entertain my demands, especially bigtime ones. No matter, there are enough smalltime recruiters for me to choose from who are only too glad to cater to my demands in order to make a buck!