"Safe", I think, is relative. Not many things are out of reach of the NSA 😄
But like how a password will keep 99% of unwanted visitors out, IP whitelisting might keep out 99.9999%, and Tor might increase that to 99.999999% 😆
@dmytri Yes, you'd have to remove all references to third-party assets. Shouldn't be too difficult, I imagine...