I have never use VPN and I will never use it for accessing any online casinos, it makes not much sense on my side since there is no form of restriction in my country but just make sure that the casino ToS supports VPN before using.
To the funny aspect of this, some of the available VPN are not free, users will have to subscribe for them and pay, yet i don't know why many have developed love for the use of this same VPN not minding what it may cost them, we have to understand the the gambling systems as well have developed technologies that helps i the identification of the use of VPN, we shouldn't bother ourself much on that for use.