If you could travel back in time, how would you design Enigma and the corresponding protocol to help Hitler win WW2 so Germany does not become the failed state it is now?
You would have to bring the data about how the stuff works and how to construct it. and even then the scientists would need at least 5 years to build the stuff because the precision of construction machines is based on other construction machines which they did not have at that time.
it would be cheaper to just tell them about the A-Bomb
Anal sex is much more disgusting. But an Anus sure is tighter, even if just at one spot, unlike a vagina.
However, if you are not a retarded, insecure faggot and go for a virgin, but an experienced girl, she most likely can squeeze your dick in her vagina.