are they possible to fill through some exchangers etc?
do you tested card to card services with - it working?
I don't understand what your question is, what "exchangers"?
go to bestchange for example - then choosing BTC-VISA exchange and fill $10 to that card and use it in clearnet services
or card to card services eg yandex and direct transfer funds from your visa to this, as it been drop/anon plastic but only virtual
and yes, the most problem - I heard they valid only for US so are they working online world wide? most services not validate empty balances..