Well,
Im not gonna go to the " lazy label", I understand where your coming from, BUT... Wind will take that smell to other sites down wind of it...
It really is not fair to have your neighbors smell your dogs collection of urine.. After a few days, I am sure that pan is RIPE and smells pretty bad....
As much as it may be a bother, it would be beneficial for ALL if your were able to have the pups urinate in a different spot each time in the middle of the night....
I can imagine that the smell must be pretty bad if your asking us here what to neutralize it with...