Parallel diffusion coefficients obtained for the Reticulum (top) and Eridu (bottom) clouds in the fibre (left) and shell (right) geometries, assuming the damping rate of Eq. (5), a characteristic CR flux variation length ℓ_CR = 400 pc, and a uniform LOS depth equal to the shell one or to the average of the fibre ones. For each geometry, the Eridu plots show ĸ_‖ values for the same CR flux exciting the Alſvén waves as in Reticulum (left) or for the reduced CR flux corresponding to the cloud lower γ-ray emissivity (right).