I find the grooves on the OEM 19s a PIA to clean, then on top of the the little gap between rims annoying as well. I looked for awhile and counldnt find a good tool for cleaning them. Then one day walking around our local buchheit (farm store) I ran across the perfect tool. Its amazing how well it works and only 2 bucks..
FLP Elite Auto Care 2 in 1 Detail Brush Ideal for Vents Seams Electronics | eBay
FLP Elite Auto Care 2 in 1 Detail Brush Ideal for Vents Seams Electronics | eBay