Not being smart but have you tried
www.jobs.ie and searching under keyword? Type in Clifden, Ring, etc.
Hotels, coffee-shops, factories.. although don't take a job in a factory if you want to learn Irish!!
You could give Udarás na Gaeltachta a call. They have a base in each of the Gaeltachts so decide where you want to be and them ring them in order of preference.
They have up to date information on who is hiring and will have names of companies, for example- Nemeton in Ring, Waterford. (Depends what your experience is in but you can work adminny work/make the tea in any organisation :)
Another option is to call a local TD in that area and ask them for their on-the-ground information.