Interaction timescales of photons (left) and of electrons and protons (right), for one of the masquerading BL Lacs in the sample. The solid curves show the total interaction timescales in the best-fit scenario (cf. Fig. 5). The two peaky features in the magenta curve result from resonant photo-meson interactions between protons and broad line photons, due to the proximity between the dissipation region and the BLR. The dashed curves show how the interaction rates would behave without the presence of external photon fields, as in the case of true BL Lacs.