I find this change of scene perfect. First we are following poor Aelia, in the middle of the mob, experiencing just a bit of what she must be enduring. The insults, cat calls, people hating her. Must be really terrible, feeling to be in the hands of people hating you, condamned to die a hideous death. A second later we are in a side street and the horror of the thing seems a bit farther. One is even telling that this punishment seems to be too harsh. But then we hear Mommius saying that she deserved it, he seems to be even proud to have raped her, and waiting for more tortures. No hope for her!
About the salt, I guess that it was not unusual among Romans rubbing salt in the wounds or pouring salted water; it should have some anti-bacterial properties, I do not think they had many other alternatives. In the case of a condamned this most probably had the effect to limit the bleeding and the infections, so that it could last more on the cross. Of course this was excruciating, but who cares!
There is one scene that has striken me so much. When Aelia has just been scourged and is unfastened by the pillar, but that they have unfastened only one wrist, so that her body is half turned toward her tortures, her head hanging, her chest heaving, her back a mess of welts, her skin in ribbons, and her front still almost intact, creamy, silky. Striking!!!
