Question

What do I do with the key item "Grubby Hanky" in B2/W2??

Answer 1

You return it to the Cafe in Nacrene City.

Source

I heard you return it to a person with a Patrat. That person isn't always there. From here.

Comments

lol. I beat you by TWO seconds.

Answer 2

At the cafe warehouse in Nacrene city.