I get so angry with chinchilla books. 95% of them are wrong. What happens is a freelance writer decides to write a book about chinchillas (which they know nothing about) so they then hunt for sources. They take interviews and then use the info to compile their book. Sometimes it is quoted right and sometimes it is not. I was a source for one of the new chinchilla books and they didn't even get my information correct in the acknowledgment! After seeing that I didn't even bother to read the book.
Now I only recommend books written by known authors in the chinchilla world.
I did a little research on the wood thing because I know cedar is a bad wood since that lovely smell it gives off causes respiratory problems in chinchillas and I know the oleander is poisonous.
In my
Joy of Chinchillas book which was written by chinchilla breeders (one of whom is a vet). on page 12 it says Never use cedar, plum, cherry, oleander or redwood.
Non-toxic woods include peach, apple, birch, aspen, maple, willow, manzanita, and hazelnut.