The idea that the basic features of the CMB were at least in part due to thermalization by cosmic dust was an auxiliary hypothesis to cold and tepid Big Bang explanations and later to the explanations within variants of the steady state model. David Layzer started developing his cold Big Bang views in the late 1960s, epistemically motivated by avoidance of Hot Big Bang ad hoc assumptions about initial conditions, while sticking to explanations based on regular known processes as much as possible. He argued for early favorable conditions in a cold Big Bang, which required the auxiliary of thermalization of the CMB by grains. Different physically plausible shapes of grains were devised, from hollow spheres to elongated ones, along with their different observationally plausible content. Explanations of the dust’s exact appearance during the evolution of the universe also differed.