Cheap white vinegar from the grocery store mixed with 3 parts water and poured over the plastic grass with a watering can will kill off the urine smell very effectively.
I don't know about your location but I can get generic branded white vinegar 2 litres for $1.40 where I am.
MrSquigglesRocket t1_j7tynml wrote
Reply to Solution for dogs on artificial grass on concrete? by andraspberries
Cheap white vinegar from the grocery store mixed with 3 parts water and poured over the plastic grass with a watering can will kill off the urine smell very effectively.
I don't know about your location but I can get generic branded white vinegar 2 litres for $1.40 where I am.