Yes - tried lots of things. Having caught thousands over the 30 years I've fished the Red I have had ample opportunity to try many sizes and in many seasons.Have you tried an overnight soak in buttermilk? Gotta get all the red meat and yellow fat out of the fillets as well.
Saw the English chef w/cooking show on outdoor channel (Mike Robinson) bleed, gut, and then tail-hang fish overnight on last night's episode. They were in way Northern Finland spearing cod and "flatfish" intending for Halibut but got a Plaice instead.
They talked about hanging fish from the tail in the "not-quite" freezing cold helping to "set-up" the fillets. The fillets sure looked nice and blood-free.
I bet that bleed-out and tail hang would work for any kind of fish. A deep/talll cooler with a little ice @ the bottom oughta do.
Yes - I have been aware of the red meat issue for many moons - even bass aren't half bad IF you remove the red tissue.
RR cats are not only oily but they have that "fishy" taste. Even smoked em... to no avail. : (
Tailrace cats are edible - oily (smelt eaters) but they're edible.
Red River cats are simply a different kettle of fish for some reason. I eventually just gave up. Maybe it's because I live downstream of Fargo and they're eating liberal turds.