Im thinkin let the trout slightly taint. Just so when you smell it you say yep, its goin bad! Stop it right there with S.B. and M.P. Add some beaver castor and enough glycerin to keep it from freezing. Not too heavy on the castor. Just so you can pick it up in the back ground. I would then add one drop of skunk ess to every pint of the batch to kick out the odor but not so as to pick it up with youre nose.