Most FTs in China never use agencies. They contact the schools directly.

Every employer of FTs in China has annual turnover, usually at the end of each semester.

Some of the schools do advertise directly. Some do not.

In either event, you should choose an area in China where you want to teach. Then compile a list of employers in that area. Locate the email addresses of their Foreign Affairs department. Send an email with your resume to each of them.

All of this information is available by googling the the school names. Many lists are available on-line.

If you are credentialed, when you send 100 resumes you will probably receive a number of offers. All FAO staff are able to communicate in basic English.

Idiotic agencies often publish the names of their school clients in their advertisements, feel free to search for the contact information for that particular school and send your resume directly. Simply explain to the school you sent out many resumes to schools in the area.

All of this is actually easier to do if you are NOT in China, given the restrictions on Google here.

If you are unable to do internet searches and send emails, you shouldn't be leaving your home country.