I have never found lack of scales being any issue with affecting their ability to catch fish with. My father in law started me getting my bait from these sales (North Vancouver was the first one I went to) 25 years ago and have gotten them from these type sales or direct from commercial fishermen ever since, and every year. It's the scent and the salmon seeing regular bait they feed on that matters for getting them to bit. A flasher gets them attracted in the first place. If you want added attractant then add colored brine, glow/UV teaser heads, or flash tape etc.
I use these in all different sizes for salmon from the very smalls (not many in these sales though) right up to the jumbo's. I use them whole, in teasers, in strips, and cut plugs. They all work excellent. I catch the majority of salmon with these Herring and with Anchovy but more with these Herring. I still have some left from last season but will be stocking up again this season as I also get lot's for buddies as well. I use them for everything; salmon, Lings, Hali's, crab and prawn bait etc.
When I use the jumbo's for strips I keep all the heads/guts etc, freeze that, then crush/mix it all up and toss it in with prawn pellets for excellent bait for crab/prawns etc.
Also get my brother a bunch from these sales and he mixes it in with home made dog food to give his dogs some added nutrients they otherwise wouldn't be getting.
They keep very well vac packed and if you want you can cure them up before hand to make them keep even better vac packed.
https://www.sportfishingbc.com/forum/index.php?threads/2019-herring-for-autism-sale.72848/
