Virtually all polymer guns today use one or another formula of glass fiber reinforced nylon plastic.
These plastics are extremely solvent proof, and most common solvents won't attack them.
With that said, stay away from things like automotive cleaners like carb or brake cleaners.
You can use most liquid soap type cleaners, but note that many of the stronger ones WILL attack aluminum.
Painted on features like safety markings and dots or bars on sights are paint and ultrasonics will eventually remove the paint.
Use a more aggressive solvent that attacks paints and ultrasonics will strip the paint almost instantly.
For solvents, you can buy several that are made for use on guns. These are often sold by the companies that make the cleaners.
As example, the cleaners that are being sold for reloaders usually have a gun cleaning solution listed.
Another, albeit rather expensive cleaner solution is Cylinder & Slide Shop's "Dunk-Kit".
This is a bucket of a cleaner/lubricant.
It's made to simply drop the gun in the bucket and let it soak. After it's clean, you shake off the excess and it leaves a coat of a lubricant on all parts.
I'd still recommend using a dedicated lubricant on key parts.
This also works well in an ultrasonic cleaner, and eliminates having to rinse and dry the gun then apply a lube to prevent rust.
