A recipe for sanity: Water, salt, nothing else. Nothing.
This summer, I spent an hour floating in a 4-by-8 isolation tank filled with tepid salt water in a basement in Manassas.
No, this wasn't a "Silence of the Lambs" scenario. It was an exercise meant to bolster my sanity, not endanger it.
Floating in a tank of skin-temperature water saltier than the Dead Sea is said to induce an ethereal, meditative state - one that doesn't necessitate furtive handoffs on street corners or haggling with sketchy dudes who listen to Grateful Dead bootle...