I agree with you that the use of WD-40 on *chains* is probably a bad idea (and thanks for pointing that out), but I was suggesting its use for cleaning wheel rims and spokes, not chains. Grime and hardened chain-lube (on the wheels) just wipe right off with WD-40 (prior to sudsing up the bike). Of course, then you need to sponge-off the WD-40 during the wash.
I know what a grunge brush is and I use one on my chain together with an O-ring safe chain cleaner. They really make chain cleaning much easier and more effective.
Re. cleaning the wheels, it depends to some extent on what chain lube you use; some fling-off onto the wheel a lot more than others (even though they say they don’t on the label). Another benefit of washing wheels, especially if you have wire wheels, is that you can check for loose or broken spokes while you’re doing it (I recently found a broken spoke on my bike), but yes, I agree, cleaning wheels (and bikes in general) is not much fun.