Yeah, I considered doing that to my Cannondale back in the 90s. The idea was to polish it out, then put parts anodized in a few different colors on it. This was during the color anodizing craze.... Remember Paul derailleurs?
Never did get around to it... Other priorities at the time.
Anyhow, I've polished quite a lot of aluminum and can give you a couple tips.
Do not bead blast it. If you do that it will triple your work, as you will need to start with a coarser grit sandpaper to remove the bead blast texture. Chemical stripper will go fast. Stripper is way less nasty than it once was, but still, do it outside with a respirator.
For home polishing, wet sanding by hand is going to be fastest. The finer grit you start with the less work it will be. Each grit has to obliterate the sanding scratches from the previous one. With aluminum, you don't need to work up to super super fine grits like you do with lacquer. You can often go from about P600 directly to polish. Maybe P1000.
Sample finish/polish schedule:
Chemical strip
clean up with 0000 equivalent scotch brite
P400 in soapy water till it's nice and smooth
P600 in soapy water till sanding scratches from above gone
P1000 in soapy water till sanding scratches from above gone
hand polish with Simichrome or Ween or equivalent and a cotton rag
Clean with naphtha and give it a light coat of lacquer if desired. I like Mohawk tone finish lacquer for this. Or just wax it and repolish every few months.