Check the voucher master thread on the AA forum: https://www.flyertalk.com/forum/american-airlines-aadvantage/578068-transportation-voucher-vouchers-mco-faq-master-thread.html
It indeed seems like you will have to route via the US for eligible AA-coded flights - this is not attractive at all.
There is no 'trade currency' for them. Your only and likely best option is finding someone who would be able to use them on a flight to or via the US and get them to pay you for that. You can redeem the vouchers for other people - AA has let me use vouchers for non-relatives with no questions multiple times.