Re: Anal Sex
I didn't realize there were different 'types' of anal sex. You're probably going to have to explain which way is the type that can kill you because I've never heard of this.
Any type of aggressive anal penetration may potentially result in a tear, which may result in an infection which may result in ... (etc. etc. worst case scenario). But unless you explain what 'type' you mean, we'd just be guessing.
As for using it as birth control, have you considered actual birth control? Or outercourse? or oral sex? These are also viable options.