I don't have access to Sand Blaster, or Glass Bead or Walnut. Plus, if I rent one at Home Depot, don't I need an enclosure? I don't know too many places that do this off hand and I'd rather not pay it if it's more than $40.
The hardest part is the fins and those in between spaces.
I don't have a pressure wash either and am doing all this in my front grassy yard.

Ah, but someone mentioned using
Gun barrel brush. They can get quite pricey. Some of them have a minimum order.
http://www.solobrushes.com/WebCatg2.asp?Cat2ID=6&Cat1ID=4
or this website is good too:
http://www.brushtechbrushes.com/index.php?cPath=1
I hope people would start putting down how much things cost to sand blast with walnuts or whatever because we all would like to know a cost effective way to do things. Don't be modest, it's not like I'm asking you your income.