I did the same thing this afternoon. I now have a new ideas for what I will buy next time for aftermarket wheels.......something that doesn't require a toothbrush A winter full of automatic carwashes didn't help anything.
Can't wait for SPRING! I haven't given mine a bath since the day I bought in December. Even if it's warm out - all the snow is melting and road get salted so they don't ice up overnight. Soon enough.