Stretching the Achilles can help particularly if coupled with the other recommendations. If you do stretch on a stair or firm incline, science has proven that you must hold the stretch for at least 3 minutes to get any value out of it. And then it’s minimal. The muscles that cause PF are so deep that seldom will stretching relieve and resolve it. So couple the stretching with the other recommendations and it can compliment the rehab process.