I am not sure what the Confessional looks like, since I have not seen Trigun, but I have a feeling this idea might be difficult to get across without a small amount of spoken dialogue, or at least an intro that explains a bit to the audience what is happening. Not knowing the show, I think this performance would confuse me unless I had some sort of preparation, or some spoken indication of what you were trying to convey. I wouldn't know you were offering confession. I would see you running around the stage, frantic, begging people about... something, then leaving the stage. "Flight of the Bumblebee" would only add to my confusion. I would most likely think your character is somewhat spastic/panicked, and that's not what my impression of Wolfwood has been from other presentations I've seen.
First and foremost, I would definitely choose another piece of music. If you decide to go with the same idea of him trying to convince people to take confession, I would consider something that sounds as if it would play in a church (such as a hymn played on an organ). That way the audience knows you are trying to convince people to do something that would be considered a religious activity, or that the setting is in a church.
Secondly, I would strongly consider adding either a couple lines of dialogue to make it clear that you are asking people to confessional or including a description in the intro of what your activity is. Asking people to take confession wouldn't be something I would assume for a skit, and not knowing the anime, I would be very confused without a little help. For example, off the top of my head, an intro such as: "Wolfwood, wishing to help souls find salvation in any way he can, invites those around him to confess their sins and seek redemption." Or something else that tells a small amount about his character and what his motivations are for asking people to take this confession.
Good luck with your performance!