I do not think it is at all accurate. We can't know what really went on in the Radley house. The kids received their information about the Radleys from unreliable sources... people who would likely make up stories.
We tend to do this when dealing with the unknown. This unknown is certainly what stirs their curiosity, but that doesn't mean their game is at all true.
The Radley's keep to themselves in relation to the rest of the town. If one was to INFER what actually goes on in their house, I am sure they each have their own hobbies and individual activities that they do to keep themselves busy.
Led by their imaginative new neighbor, Dill, the Finch children spend much of their summer creating their own dramatic version of what they think goes on at the Radley Place. The kids play-act about Boo and his supposed exploits: Scout played Mrs. Radley, Dill was old Mr. Radley, and Jem took the part of Boo. The game progressed along with the summer, and the cast "polished and perfected it," adding changing plots and dialogue daily. Naturally, since the kids knew little about the mysterious Radleys, little of what went on had any accuracy. Boo probably didn't eat rats and squirrels nor bite off his mother's finger, and he likely did not "whittle away all the furniture in the house." When Atticus finally witnesses a bit of their play and catches them with scissors, he questions them if "this by any chance have anything to do with the Radleys?" Jem lies and tells him "No sir," but Scout realizes that the play's life is limited. Meanwhile, Scout thinks she hears laughter come from within the Radley Place: The children apparently have an unidentified but satisfied audience after all.
I do not think this is accurate because the kids decide to make up a game about what Boo Radley did and how he was sent to jail. They were guessing what Boo Radley has done and made up stories according to that. Their own stories may have been shifted by what they heard within society.