You mentioned two examples: (1) an existing fireworks stand that is allowed to operate at the same location although the sale of fireworks is otherwise prohibited; and (2) a sign that was erected in violation of a zoning ordinance but which has never been removed.
New hair will not grow back in the previously waxed area for four to six weeks, although some people will start to see regrowth in only a week due to some of their hair being on a different growth cycle.
About one month after the first laser hair removal session some of the hair might be gone, but some hair might also be growing back. The hair that is growing back is the new set of hairs that was unaffected by the previous session and that needs to be treated.