@cyndanna Whether you can boil or steam a mesh nebulizer depends on the specific unit. I previously owned one that could be boiled, but it is no longer sold.
I currently own the very expensive Pari eFlow Rapid, and it has done just fine with being soaked in antibacterial Dawn, rinsed in filtered water and weekly boiling in distilled water.
Cleaning according to the Mikiss instructions on the Amazon site, or simply using soap and water, increases your risk of getting infections.
Inexpensive self-cleaning mesh nebulizers typically cannot be boiled or steamed, but some may be able to be cleaned by soaking in alcohol. The question is how this will affect the mesh.