Tongue and groove board behind drywall, how to handle the corners?

[Snailman]

[link]
not the same thing

They have several models through that link, 86815 resembles k-rautas in your link.

 

[SBH]

They have several models via that link, 86815 resembles the one from k-rautas in your link.

does it have glue that you only need to spray water on?

 

[Snailman]

does it have the glue that you only need to spray water on?

Don't know, probably not.