I'm not an AR guy, but in the R/C biz we use oven cleaner to remove anodizing from used parts when the finish is damaged or the colors don't match. Usually leaves 'em in a nice natural finish after about 30 minutes and can then be clear-coated to prevent oxidization.
One thing I CAN say for sure - anodizing lasts longer on media-blasted surfaces than it does on tumbled/polished surfaces... as with most industrial coatings the life of the finish is all in the prep work before it's applied. If it's slightly rough under your fingers (looks parkerized), it's blasted or acid etched. If it's mirror smooth it was probably tumbled to remove the machining marks and you need to be gentle.
Gonna go with Murdoc and the laquer thinner.
You can test your chosen cleaner by soaking a grade 8 steel bolt (a grade of high strength steel that is anodized yellow) from the hardware store. You probably have a few in yer garage. Not fool proof but getting closer.
As for brushes, if it has bristles it's ok for anodizing - if it's a brillo pad kinda deal it's not. Most pads are too abrasive and will haze your finish.
Since this is a gun part that probably cost more than some of the crappy old bolt actions in my cabinet, proceed carefully. If it's a currently produced part a quick e-mail to the manufacturer or distributor?
Let us know how it works out please... Pictures always appreciated
