How do you test your offers from different countries?

Im doing a lot of email submits. And it seems that 50$ of the advertisers suck balls. They pay for 1 in 5 leads. So to protect myself I like to test them.

Its cool when Im using offers from canada because I live in canada and it works fine. But when its offers from the us or uk it plan sucks.

Ive tried with proxies but its very frustrating beacause a lot of free proxies just dont work with cpa offer either. Maybe theres a way to have them work?

I dont know. What do you guys think?