it was one of the lads in scotland that put me onto it. He has 2 plastic bins behind his house with holes in the bottom to let the liquid out, guts any spare mackeral or herring, chucks em in and covers em in salt, keeps topping up till full. the lid goes on and it sits there till the till he's emptied his first bin then swaps em over. the mackeral he'll start using at easter may well have been sat there since last july! the smell is an acquired taste!
Didn't notice much difference to the number of crabs/velvets I got, but the frequency of lobsters went up, from maybe one or 2 a week, I'd some times get one a day from 6 pots