Smeargle quest postgame (spoiler)

[Simardel]

At the nightclub only the smeargle appears and he says "human go help door in stinky wet place", where do I need to go?

[Blontary]

May be the one in byxbysion? I don't recall, if it is that You access it from tanzan cove 

[stardust03]

I believe that's the one in the water treatment center.

[nguyengiangoc]

1 hour ago, Simardel said:

At the nightclub only the smeargle appears and he says "human go help door in stinky wet place", where do I need to go?

https://docs.google.com/document/d/1n0MGk8DAMW4lsbUh26LCoBtm1N0_AHQH_2ahvjaTAnY/edit