Aircraft paint stripper works awesome. Bag your parts and use a WD-40 nozzle with a straw and squirt everything down in the bag. Cold water rinse and they are fresh parts again.

Seal the bag and it will expand, but burping it will allow you to watch it strip and turn the parts.

Aircraft stripper is non caustic to aluminum, but has the full strength of regular stuff. Some are non-toxic. Always wear gloves. Latex surgical gloves hold up to it.

I found my can at AutoZone for about $6. Whatever brand, just make sure it is stated as being aircraft stripper.