Various addictions counsellors are in recovery from their own addictions and this can bring some value to the clinical process. Other addictions counsellors have no personal experience of being addicted and have studied extensively to be able to work in the field.
I believe it’s important to have a good cross section of staffing in an addictions treatment centre and critical that if any staff are in recovery that they have the appropriate education and accreditation, as well as police clearance, to work with addicted people. Some of the lower quality rehabs employ addictions counselling staff that have very little or no formal education and supervision. I would suggest staying away from these centres and find clinics that employ accredited addictions counsellor.