All of the OTC wheel cleaners are safe to use on alloys...the cutting agent used in most cleaners is citrus based and safe to use...they have to be for the general public to use without causing staining.
Mothers, Megs all have good OTC stuff
If you want something online then check Phils site to see what he has
Like the other fellows suggest, the otc wheel cleaners will work just fine if you clean your wheels on a regular schedule like weekly.
A tip for the P21S gel - Harley dealers often have the S100 gel in stock. Since the S100 wax is rebranded P21S wax, I'm thinking the wheel cleaner gel may be the same. If you have a big Harley dealer close, it could save you a little time.
If you clean your wheels only twice a year then you'll need something stronger than any otc product.
Like you ask, a non-acid based very strong wheel cleaner is Brown Royal and it's safe for clear coated wheels and bare aluminum wheels when diluted 4:1. Brown Royal will handle the crud the otc products can't touch. Mail order/online only but quick shipping.
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