hcg should be used on cycle. NEVER as part of your pct. You can run it up until 4 days before you start PCT but DO NOT run it during PCT. It is a suppressive compound and will not allow you to recover if you are on it while you are trying to recover.
The reason it is more beneficial to use on cycle and not just during the time between the end of the cycle and the start of PCT (which is an old school protocol btw) is because HCG mimics LH (Leutinizing Hormone) and in doing so keep you testes 'awake' during the cycle and doesn't allow them to atrophy. This will allow for a much smoother faster recovery because you testes will actually be able to receive the signals sent by the pituitary gland during PCT. Atrophied testes will not be able to receive these signals (hormones LH and FSH) because they are essentially dead. It doesn't matter how well you stimulate you pituitary during PCT if you testes are dead youre fucked. And one will often run into this issue using HCG only during the period between the end of the cycle and the beginning of PCT because his testes will have been turned off for too long. Why let them shut down completely and then try to restart them if we can use HCG to never even allow them to shut down? Make sense.