Appropriate action includes:

(a) Prohibiting the individual from making, on behalf of any other person (except the United States), any formal or informal appearance before, or with the intent to influence, any oral or written communication to, DFC on any matter or business for a period not to exceed five years, which may be accomplished by directing DFC employees to refuse to participate in any such appearance or to accept any such communication.

(b) Taking other appropriate disciplinary action.