why does Elisa take such a thorough bath?

Elisa takes bath, scrubbing herself with a little block of pumice, legs and thighs, loins and chest and arms, until her skin was scratched and red (90-95). This symbolizes that she is feeling guilty for her attempts to cross these boundaries of society. Apparently this means her foray into the world of the masculine and the feminine takes its toll. This corresponds to her relationship with the tinker (he brings out the woman in her!) and her husband (he makes her feel like a man!)brings out much guilt in her. Elisa seems to be trying to really wash her guilt away, the scratches being a sort of penance.