Se en voix passive

[Robert]

Which of the following statements is correct? If both are acceptable, is there a difference in meaning?

Je me suis mis à utiliser l'homéopathie.
Je m'ai mis à utiliser l'homéopathie.

Thanks for looking at this.

[Grégory]

Only the first one is acceptable. The second one is not french :)

[George Hunt]

No ,your second example is completely unacceptable , Robert (go to the back of the class ! )

[Robert]

I knew it , just wanted to be sure.
This would be good then? : Je lui ai mis à utiliser l'homéopathie

[George Hunt]

Not really. You mean you "made him start to use homeopathy"?

Your French sentence makes no sense to me.

You could have said
"Je lui ai conseillé à utiliser l'homéopathie"

If you want to say something like "I started him on a homeopathy course" you might say perhaps

"Grâce a moi ,il s'est mis à utiliser l'homéopathie"or "C'est moi qui l'ai poussé à utiliser l'homéopathie"

[Robert]

It's easily a doctor's plan, or a spouse's. But thanks for the variations.

[Antoine Olivier]

It's "Je lui ai conseillé  d'utiliser l'homéopathie" instead of "Je lui ai conseillé à utiliser l'homéopathie"

[George Hunt]

Thanks.That is a weakness of mine.

[Grégory]

If one adds 'être' to 'se mettre à' that doesn't form the passive present but the active passé composé, 's'être mis à'.

Robert, I think the closest of your uncorrect sentences is 'faire se mettre qqn à quelque chose', e.g. 'Je l'ai fait se mettre à l'homéopathie' (p.composé) or ' Je le fait se mettre à l'homéopathie' (present) which are completely correct. 

The pronominal constructions including the semi-auxiliary 'faire' don't express passive voice. They express what is called in linguistics causative voice. In the example above : I caused the fact that he started homeopathy, or something like that. Actually I think that passive voice is impossible with reflexive pronominal verbs for logical reasons. So using 'faire' in causative sentences is a solution to express a sort of passivity.