Probably a stupid question but why not offer your services to one of the two SAC sections here or the Amis Montagnards, Piolet club, Geneve rando to mention but a few.  All of these clubs are taking out groups which are predominantly francophone (ie Swiss romand or France voisine) and forces people to be immersed in French/Swiss culture.  Whereas a group of glocals remains a group of glocals.  

There is also a group of accompagnateurs in Geneva which might be of interest to you.  I do not know what level you have but these are 'guides de moyenne montagne' who I think have followed a two year course which involves geology, botany etc but they charge for their outings as it is their full time employment.  

Hallöchen, Willkommen bei Glocals!

It's a great place to meet nice international people. The best way indeed is to attend or organise an activity. Since I met some people who wish to improve/practise their German - you might organise an easy hike with German conversation. Just a thought.

So have fun!

Hi Pauk,
Thanks for your suggestions. Actually I am an "accompagnateur de moyenne montagne" ("mountain leader" in English)!! Are you talking about the association "les passeurs de col" ?? I know some of them.
It is not yet my full time job, I'm starting slowly...

Well congratulations!! Hope those reading this understand the training you have had.  Yes les passeurs de col.  I know both Guy Trottet and Geneviève Fol because they are both members of the Geneva section of CAS and involved in the commission which is trying to create a maison de montagne in Geneva.  Both of them very nice but not sure hoiw they react to competition as they are full time accompagnateurs/lecturers. 

I will follow your posts with interest but unlikely to join as am heavily involved in organising walks myself but without the in-depth knowledge that you have.  You are welcome to come on any odf the CAS alpine tours I organise whether or not you are a member.  Some of them will give you a good introduction to the area esp Hte Savoie with which yo are maybe less familiar.  The walks are conducted in French/ English - leider kein Schwyyzerduutsch - sorry cannot spell that but then I believe spelling is up to the speaker.   

Grüss Dich just_me,
Thanks for your interesting idea. I will think about it...
take care and see you!

Thanks for the invitation!
I know Guy Trottet, actually he is the one which gave me the lust to become a mountain leader.
Can you tell me more about the "maison de montagne" in Geneva ??
Take care

PS. your swiss-german is just perfect