There are a couple I know of who have been in business long enough to be worth risking, but I would not unless you really need to.
They allow people from banned jurisdictions to access books like
Pinny and
Betfair again, as well as a range of Asian books. Arbitrage bettors also use them as it is easy to shift money between several books without cost or waiting.
asianconnect88.com and premiumtradings.com websites will tell you all about what they do.