Dont know how I missed this post!

The thing with polished wheels is to keep on top of them - wash them often with as mild a product as possible, ideally just soapy water. Id recommend sealing them with something durable; nano wheel sealant.

At a mild dilution, there should be no real issue, so if you were considering the 5ltr RTU, I'd maybe dispense 1ltr and top it up with water, to give a milder solution and when its used half way, pop is the litre you took out, and top it up with water again - job's a good'un!