I used Bilberry Wheel Cleaner last night, diluted 1:5 I think, one wheel after another, left it to dwell for 5 minutes as the instructions say you should, but after 5 minutes it had practically dried out! The sun wasn't out and it wasn't that warm so scratching my head as to what's going on. It pressure washed off fine at least.

 

I know Bilberry is/was a popular wheel cleaner, so wondering if anyone else had this issue?

Instructions:

Never apply on hot wheel surfaces. Rinse the wheels thoroughly with plenty of cold water to remove loose dirt and to cool the wheel surface before application. For best results, clean only one wheel at a time. Spray the Bilberry Wheel Cleaner onto the wheel surface and agitate with an alloy wheel brush to create a rich foam.

When the wheel has been cleaned, rinse thoroughly with plenty of cold water. Do not allow the Bilberry Wheel Cleaner to dry on the surface of the wheel.

 

I suggest you left it on too long

Spray and wash off within a minute