I've become fascinated recently with the idea of total sensory deprivation. I've been looking into anechoic chambers and floating therapy chambers and how they work, but both seem to lack complete annihilation of all sensory experience (anechoic chambers leaving room for rustling of clothes and talking to yourself, therapy chambers being little more than dark pools of saltwater). While I do my own research, could someone with maybe more insight tell me about what I should expect and the closest thing I can get to ultimate silence and darkness?