I believe your talking about D + G eggs, they're the ones that come in the plastic containers. I'm not exactly sure what cure they use but I believe it's a heavy sodium sulfite, a lot of salt, dye, this way they do preserve longer considering they have a long shelf life, they also drain the eggs in the middle of the curing process to produce that gummybear texture. I'd rank store bought eggs behind sandshrimp and would recommend the shrimp especially for winter steelhead.

Or if you get a fresh skein of eggs I'd recommend (Ultimate Egg Cure when it's ready) but pro-glo or pro-cure are great cures also. Follow the curing instructions on the label. Just make sure to clean the blood from the eggs before curing them.
Hope this helps.
Keith