I'm building a Battle Tree team, and I wanted Black Sludge for my Toxapex. I just want to know how to obtain it, since I already have a Pokemon holding Leftovers.
Thanks in advance! :)
You get it from wild grimers. 5% chance. Best thing to do is get a butterfree with compound eyes and thief and S.O.S chain grimer till ya find one.
Source:Experience, and this: https://m.bulbapedia.bulbagarden.net/wiki/Black_Sludge
The only way to get Black Sludge in USUM is by using Thief on a wild Grimer. They each have a 5% chance of holding it. Source: https://m.bulbapedia.bulbagarden.net/wiki/Black_Sludge
Grimer have a 5% chance of holding a Black Sludge in the wild.
Hope this helped!
Source