I have not heard this before "you do not need to put a comma before which, unless there is a complete sentence afterwards?"
Consider this sentence:
Apples, which are my favorite fruit, are the main ingredient in this recipe.
I disagree with the concept that you do not need to put a comma before which, unless there is a complete sentence afterwards.
It is true that you don't need a comma before the as for sentences like these:
Return to the clinic as recommended.
She will return to the clinic as needed.
She blah blah blah as described above.
Antipsychotics as per the treating physician.
The rule is that you don't put a comma between the two verbs or verb phrases in a compound predicate.