We actually do

But how to include this in random conversation with oblivious people without sounding psychotic or sexual

we Hungarians say Leszarom which means I shit on it

I had always heard "Das ist mir Hackfleisch"? Or is that a Koeln thing?

In french we either have :
Je m'en fous ≈ "I'm getting fucked [over that statement]" (hard to translate litteraly. As fuck.)
Je m'en bats les couilles ≈ "I'm beating my balls [over that statement]"

This actually means "i don't care" or "it doesn't matter to me."

You deserved it for being too addicted to your shitty blog to watch the road.

This post is sausage to me

Actually, we also do say "I don't care"
But "Das ist mir egal" (I don't care) and "Das ist mir Wurst" (that's sausage to me) do have the same meaning.
We also have "Das ist mir Jacke wie Hose" (that's like jacket or trousers to me)