And they are often breaking Trust policies...
If you look carefully at most procurement policies reps are only allowed in after having contacted the purchasing department and sought permission.*
In a previous job I asked our head of precurement to write to the company MD saying we would consider banning a rep if he continued sneaking in - no rep=no potential for any sales. It stopped him.
RoJo
* Though this is often subcontracted to Clinical Engineering etc by mutual agreement and to save the purchasing department all the hassle.