A proposed promotional practice filed pursuant to these Rules and Regulations may be implemented by the applicant thirty (30) days after the date of filing unless the Commission, upon its own motion or the motion of any party, issues an order suspending the implementation of the proposed promotional practice pending further investigation. However, the suspension shall not be for a longer period than one hundred fifty (150) days beyond the time when the proposed promotional practice would otherwise go into effect. Any order initially suspending a proposed promotional practice shall set an appropriate procedural schedule and a specific date for the commencement of a public hearing inquiring into the proposed promotional practice unless waived by the applicant.