I have had no problems with the ryoshi/ryobi or similar sounding brand from the warehouse. I normally keep several rolls on hand because it is easy to lose. I buy and use any thin looking bait elastic, it is just elastic at the end of the day nothing super high tech.
edit: Smith city (at-least the Blem branch) has bait cotton at the moment, I did not buy any but it appears to be a stocking like material which can completely cover extra soft baits like mussels. Next time they have a sale I would buy a pack or three.