Nowhere have I suggested that the 'placebo effect' always works, it's merely used to remove variables when searching for a prognosis. If you were a legitimate 'medical practitioner' I wouldn't have to explain this to you.
"...how can it cure them by the placebo effect, which according to you is the only possible effect a remedy can have?"
At no time have I claimed this, this is another 'straw-man' fallacy.
As far as 'diagnostic technique', it would completely depend of the symptoms of any given circumstance.
I've responded to you, reasonably thoroughly, may I request you return in kind. What qualifications does one need to be a Homeopath? Who is the regulating authority to which Homeopath must conform? Who to people contact should they have a complaint about a Homeopath?