Wouldn't the metal be quite... cold?

Just seems to be a less serious comment in this thread. There are lots of ideas.

Thanks; I think that's core to the problem of us not finding a solution: we are biased to think about complex and fancy ones.

My comment intent was absolutely serious and a humbling attempt to study the problem without bias.

(but as others have said in the comments here, I also do not think that a casual discussion on HN is as good as the studies done so far)

How would you use this as a sex toy