Funny, in Sweden where surströmming is from I have heard the exact same words used to describe the production of Hákarl. But Hákarl is easy to smell and eat compared to surströmming, which is gut-wrenching when you smell it.
I think they wash Hákarl before packaging it while Surströmming is still fermenting in the can until opened. The right way to open Surströmming is to submerge the can in water and wash the fish before serve. Much less smell.