Spritzee, the perfume Pokémon from Kalos, can be found in the wild in Pokémon Go. Yes, Spritzee can be shiny in Pokémon Go!
Neither Spritzee nor its evolution Aromatisse see any use in meta play, but it does have a pretty good shiny!
What is the shiny rate for Spritzee in Pokémon Go?
As per old research by the now-defunct website The Silph Road (via Wayback Machine), the shiny rate for Pokémon on a regular day is approximately one in 500. Spritzee is not a confirmed Pokémon that gets a “permaboost” (meaning that it’s a rare spawn and thus gets a boosted shiny rate).
What can I do to attract more shiny Pokémon?
Not much, unfortunately. It appears to be random chance. Shiny Pokémon catch rates are set by developer Niantic, and they are typically only boosted during special events like Community Days or Safari Zones, or in Legendary Raids. There are no consumable items that boost shiny Pokémon rates.