With channelling, what you generally get are the words of the spirit filtered, coloured, and interpreted by the mind of the channel.
One of the most difficult things for a channel to do is to get their own minds completely out of the way, and resist the urge to interpret what the spirit is saying, rather than simply relaying it.
Before you purchase a channelling from someone, I recommend picking up a copy of Spirit Relations by Bill Duvendack. The book gives a great breakdown of what exactly channelling is, what it isn’t, and how it differs from mediumship.