Like BJH, I also use a hardware store variety fine wire wheel. In fact I just bought a replacement .006" wire wheel today at a garage sale for $2.00. I mount my wheel on a threaded rod and chuck it up in my variable speed Jet 12" wood lathe. Best slow speed motor I have in the shop.
To answer your question, I have had a 4 row .0025" Brownells wheel sitting in my shop for probably 20 years and never used it. Looking at it, and this is just my opinion, I think a 2 row wheel would be too soft. I think the additional 2 rows in the 4 row wheel adds a bit of needed rigidity. I should probably mount it up sometime and give it a try.
David