One of the first things I changed when I started my longer hair journey was to stop using a brush and always use a wide tooth comb! It was a little strange at first but I gradually got used to it. This advice came from a long hair salon owner in 2004. Long hair should mostly be combed, especially when wet as the hair stretches when wet and a brush is too harsh.
A boar bristle brush can be used on dry hair to distribute hair oils. It is meant for polishing the hair, not removing knots. Personally I never use my boar bristle brush anymore as I am against using animal products.
I still use a brush once in a while, but only on the rare occasion when I am blow drying my hair, it keeps it from blowing all around. I use a oval paddle brush by Scunci(see pics on hair care page of examples). Other than that it is a wide tooth comb by Scunci.
LISTEN TO YOUR HAIR... Have you ever listened to your hair? Use a brush and then a wide tooth comb. You can really hear a difference! The brush tends to snap and pull the hair where a comb will just glide and it is easier to detect a knot.