I don't know much about catnip spray but when I looked for the ingredients in the SmartyKat mist it says: The ingredients are Catnip Oil 0.15%, Peg-40 Hydrogenated Castor Oil 0.50%, Methylchloroisothiazolinone 0.0012%, and Water 99.3488.
So it's over 99% water!!!
https://www.chewy.com/app/product-questions/130254
I did find some other brands with much higher concentrations:
Meowijuana Catnip Spray is 75% organic catnip and 25% water.
From The Field Catnip Spray Rejuvenator is guaranteed 96 percent potency (contains the active ingredient) and
KONG Naturals Catnip Spray for Cats was also recommended, but I couldn't find percentages for that product.
https://www.thehappycatsite.com/best-catnip/