I use a knotted wire wheel but not nearly as much as the 3m Scotch-Brite discs. The industrial supply place I get my where I get consumables also has these encapsulated wire wheels (see pic) but since my knotted is still is barely worn I haven't picked one up to try it.
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Basically it's a solution to prevent the crimped wire from flying out but that's what the knot does. It is my opinion that not all knotted wire wheels are the same, either. So, pay a little more for one. Mine is US made... can't remember the brand. I put an inexpensive one on a grinder I fixed to sell and after getting it together to use it I could tell immediately that the wheel would look like a crimped wire wheel, eventually.