A participatory experiment conducted in Senegal in 1998 resulted in large scale lasting empowerment thanks to the use of a time-limited support but focused on tackling hurdles inherent in contextualised social and power practices in order to launch an enduring endogenous momentum. An evaluation conducted 12 years after showed that some progresses in empowerment were made at both local and national scales. This paper is a detailed analysis of the way in which the approach achieved its impacts, thanks to a specific strategic framework, called Rainbow Spiral, which enabled the creation of an empowering contextualized process of scaling up.