2) Edible bitcoin
I heard of a place that sells a $1000 ice-cream sunday. Something about edible gold flakes in it or something (sounds sketchy, but that's beside the point). Anyways, that could be done with private keys. "Print" the key on chocolate flakes or something (delete any other copies, obv), then crumble and eat. This would be horrifically decadent, which is obviously the point for idiots who buy such things...
Not this. While it is decadent to eat money or gold, you aren't really harming the economy by doing so because there is an essentially limitless supply of both (gold is debatable, but most estimates suggest that as technology improves we will be able to access more and more of the gold in the earth, not to mention space).
The only way that this is an analogue would be by destroying private keys that don't exist anywhere else, thereby removing those coins from circulation permanently (otherwise, you might as well just eat a piece of paper with "bitc0inz" written on it). By willfully destroying bitcoins, which are already in a very limited supply and are poised to become only more scarce as early adopters die off (presumably not everyone has an iron-clad system for making sure their wallets survive them), you will damage an already small monetary supply.