You might consider a shop that does anodizing and see what it would cost to have then "dipped".
IF they are doing a "batch", they may toss it in for a nominal fee.

Trying a "brush on - rinse off" method would probably give poor results, since each area will have a different amount of time the chemicals work on them.
I've anodized small parts, where I could hold the chemical solutions in a relatively small beaker.
A crank would require a much larger "tank", and then you have the large quantity of "solution" to dispose of. That's just not practical for home use.