South African Passport Renewal by Post in the UK

Hi All

I am in the process of renewing my SA passport and want to do it by post for the first time.
All pretty straight forward except that at the end of the information form it says if renewing by post all documents need to be certified by a commissioner of oaths (COA). I have 2 passports to apply for so there are about 30 documents to certify. If they were certified by someone in accordance with the UK gov website e.g. a teacher it wouldn't be a problem but to get them certified by a COA might cost me hundreds of pounds.

Has anyone applied by post and if so did you bother with a COA or just get a policeman or teacher to certify them?

Thanks for now.

Is there a reason why you cannot go to the embassy for an appointment? I found it easy and quicker to just go there. Did everything in one go and they sent my passport very quickly. The post office route was just long.