I don't know how to deal with expired J1 because in order for Chinese Embassy to waiver your case you need to have a valid J1 visa.
Lawyer told me that the easiest thing to get J1 waiver is via "No Objection" from your current government.
Otherwise, you need to file via your spouse which is much more difficult:
The only way to get a waiver via your spouse is that you can demonstrate that your sponse could not survive without you due to extreme hardships.
I recommend you to consult a lawyer.