We discuss a general mechanism explaining the taming effect of phase disorder in external forces on chaotic solitons in damped, driven, Frenkel-Kontorova chains. We deduce analytically an effective random equation of motion governing the dynamics of the soliton center of mass for which we obtain numerically the regions in the control parameter space where chaotic solitons are suppressed. We find that such predictions are in excellent agreement with results of computer simulations of the original Frenkel-Kontorova chains. We show theoretically how such a fundamental mechanism explains recent numerical results concerning extended chaos in arrays of coupled pendula [S. F. Brandt, Phys. Rev. Lett. 96, 034104 (2006)10.1103/PhysRevLett.96.034104].