Why on earth you think they would allow you in, you have no idea. It is not like this batch of guards are going to be much different than the previous batch.
You need to get in and since you feel that you have the silver tongue, you try your best to use your verbal mastery to gain entry.
What do you say?
[It is recommended to leave here and return to an earlier post. However, if you feel that you are the appropriate skills needed to gain entry, feel free to comment below; if your comment combines savvy creative writing with a knowledge of Middle English and medieval social customs, then maybe, just maybe, you will gain entry!]