Ultrasonics only clean.
If removing dirt, dust, grime allows the plastic or metal below
to shine in the original surface, thats all.

Removing rust and oxidation, is different, and it depends on the material
and degree of issue.

Dont put plastics with any printing on them in an ultrasonic.

If you want more than just a cleaning, and you wish to ultrasonic a stronger liquid,
create a "double boiler" and use a glass jar, second liquid, and piece, in a water solution
already in ultrasonic to avoid contaminating tank, or clean cleaning solution.

It not only removes dirt and grime, it also removes polishing rouge.
Its used as a super cleaner, and gets dirt out from cracks, holes and small spaces that can take forever to do another way.
In metal fabrication, we add a steamer....something not talked about here, but essentially a super heated tank of water to 30lb-90lb++ per square inch, to blast off any extra stuff.
It sits next to an ultrasonic and used as well.
Mostly used with a rectifier, and electro cleaning, this is the last step before plating.
One can even use an ultrasonic and rinse, and use a wipe on silver plate, on some metals,
or go the whole path and learn to plate metal at home...Ventilation is always needed.

Love my steamer! Cleans the crap out of threads and small parts fast with ultrasonic!

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Heres one brand:

https://www.amazon.com/Nushine-Silver-Plating-Solution-3-4/dp/B00D5TCYT8/ref=sr_1_1

A buffed copper penny turns silver in seconds.

Sometimes, I buff a part, and it turns out plated.
So some copper or brass shows through.

I always have a jar of this, and after a buff, ultrasonic, and clean, I wipe and rub in this, and its
a restored all white metal shiny screw or metal part.

It wont do everything, but sure has saved time and money for parts to restore that cant be replaced, or just a pain to collect up and electro-plate.

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