I have noticed that it is not possible to delete guest book posts on your own guest book (If you have the Guest Book widget enabled in the profile). You can either report the guest book post, close the guest book, or just leave it there. I believe it would be quite helpful to have the option as the owner of the guest book, to be able to delete guest book posts and comments from your own guest book. I feel that this would help cut down guest book posts that could be offensive or disrespectful adding negativity and toxicity to the community. Often times, guest book posts like that would get removed after being reported or just deleted on the spot, but I feel that members would have a sense of responsibility and independence by being able to delete certain guest book posts. Thank you for reading, have a great day.