Sometimes the moisture is enough to cause a crack if there is a flaw in the wood of the pipe. Everytime you do this treatment on a pipe, there is always this chance. After a treatment, I had a pipe develop multiple small cracks on the bottom of the bowl once and that was not purchased from Ebay. Once you smoke or treat an estate pipe like that, it's yours and can not usually be returned unless there is a really nice return policy on it.