Hello!
Check out the gochengdoo website – it has listings of ESL work so might be helpful? Other than that, it’s a bit of a bugger finding short-term work if you’re not actually in the country but there’s plenty of it around once you get here. There are ads up in a lot of the ex-pat bars looking for people with your kind of background, so if you have the means to come over now that might be the best way?
Hope that’s vaguely helpful!
L d