"En vérité, Franklin est gêné = In truth, Franklin is ashamed Dan sa famille, personne ne balaie...[etc] = in his family, nobody sweeps ....Personne même ne se lave, = nobody even washes themselves ou alors, rien qu'une fois par an, = or then, no more than once a year si c'est vraiment nécessaire!" = if it's really necessary. "même" is there just to emphasis. Like saying "not even" "rien" it's understood that it follows "people don't shower". the "ou alors" would be better translated as "of it they do" (though what is said is litterally "or then"). "rien qu'une fois" is "only once". In negative sentences, we sometimes have "ne... que" to mean "only". I hope it all cleared up now!