How does Jeeves propose to solve Dahlia and Bertie's predicaments in Chapter 19?

In Chapter 19 Jeeves proposes that he can easily solve Bertie's problem of having accidentally stolen Mrs. Trotter's necklace by sneaking the necklace back into the Trotters' room during dinner. As for Dahlia's problem, Jeeves suggests that she use the fact that Mr. Trotter has turned down an offer of knighthood by threatening to reveal this fact to his wife if he does not buy her newspaper.