Using clen for PCT is a farce -- a rumor - a myth - an urban legand.
It all started with some sketchy studies on cattle that were given clen IM and showed more LBM. (Duh) THis started the speculative ball rolling in comic boks such as MuscleMedia 2000 and everyone has believed it ever since (Along with the glutimine myths, and the Nolva myths and several others)
But clen is a CNS which means, it is catabolic, not anabolic. It will lean you out, which gives the appearence of being more muscular but it will not prevent mucle loss, or restore HPTA. And any fat you lose while on it wil come back as soon as you stop using it. That happens EVERY time you use a CNS. The only way to burn fat more "permanently" is through accelerated thyroid fuction. But thyroid drugs have the same rebound effect as CNS.