The aim of this study was to experimentally determine the mixing times of viscous fluids placed in a soft container where they were mixed by the vibrations of the tank wall. In parallel, mechanistic models were established to link the inlet parameters of the crank/slider device responsible for the tank wall vibrations to the mixing times. The mechanistic models are based on dimensional analysis. Either momentum change (change in instantaneous velocity with which the slider comes in contact with the soft elastic reactor) or impulse (force transmitted by the piston) is introduced as an intermediate parameter in the relevant list of physical quantities in order to take the intensity of mechanical solicitation induced by the beater into account. These two intermediate parameters were theoretically computed on the basis of knowledge about the geometrical parameters and the rotational speed of the crank/slider device. The experimental results showed that the mixing time strongly depends on momentum change (or impulse) induced by the beater and its striking frequency. Empirical correlations are proposed, and good agreements between experimental and predicted values were obtained as the standard deviation is lower than 20% for the whole data set.