Background: In a previous work ("Matter as gravitational waves." 2012) it was set out that matter could be considered to be formed by gravitational pulsations in a hexadimensional space with anisotropic curvature, since solutions to Einstein's field equations presented many of the characteristics of a particle then. However no way that would allow the interaction between waves was provided. Results: It is shown that standing waves change propagation medium through three non-linear mechanisms: by changing the refractive index, deforming and dragging on propagation medium. Mechanical analogies of all these effects have been provided and later they have been related to Schwarzschild and Kerr metrics. As a demonstration of these ideas particle-pulse's acceleration is calculated for the "weak gravitational fields" case. The solution agrees with Newton's theory. Finally a new interpretation of Michelson-Morley experiment is provided.