Find a cause
By treating an underlying cause of postural abnormality.
Piriformis pain is an effect of pelvic imbalance either due to short leg syndrome or unequal muscle tone in the spine or pelvis. This can be done with heel lifts. You need a good thorough physical exam by someone who understands postural biomechanics. You need osteopathic doctor who actively uses manual skills to diagnose and treat disease.