I believe in the USA one must have an RX for nebulized glutathione. It's main use if for kids with Cystic Fibrosis, I believe. And it is fairly spendy, requires special shipping & handling.
Can you get sublingual reduced glutathione? In the USA we can get SL tabs of reduced glutathione fairly inexpensively. They will raise serum glutathione, too.
Best wishes.