Seaman's book options

I'm about to complete my STCW Basic Safety Training (5 days) in the UK and have my seaman's medical (ENG1), also from the UK. I don't have a job yet. I'm a dual British and Australian citizen and my understanding is that in both these countries, I need to get a job first before I can apply for my Seaman's Book.

It is my perception that I will have a better chance of getting a job if I already have a Seaman's book (and start logging sea time straight away, even if on a voluntary / unpaid basis), and I know that some countries / registries issue Seamans books to non-citizens who don't have a current contract as a seaman. I'd like to explore this possibility and as a newbie to this forum I am asking for your help.

Does anyone know of White List countries (i.e those countries properly implementing the STCW95 convention) that will issue Seaman's books to overseas applicants that don't have a contract of employment? If so, which countries? Is there a downside for me if I apply to a grey list or black list country for their Seamans' book and then convert to a different Seaman's book once I have clocked up some experience?

Thanks for helping me understand my options.