Dishwasher did a great Job

Those ultrasonic gadgets for cleaning jewellery, also work well for small parts 

Hi Martin, those parts came out sparkling!

A few years ago I used the dishwasher for a BSA B44 alloy barrel and used 2 dishwasher tablets on a hot wash.  The barrel came out very clean but the chemicals in the tablets had turned the alloy into an HMS Dreadnought very dull grey colour.  Suffice to say, I've not used the dishwasher for parts cleaning since then but I'm sure it was the tablets that caused the dullness and that some other cleaner could be substituted instead.

A lot of cleaners have a degree of caustic soda in the mix (Sodium Hydroxide) which attacks aluminium and can leave it looking like battleship grey, not a desirable outcome.

Battleship grey can soon be polished off and may well be better than the mess that went in!  If in doubt experiment with an aluminium pan or colander!