Can I ensure the worst team in my league receives the top waiver claim priority every week?

Yes, go to League » Settings » Edit Waiver Wire Rules » Reset Order Weekly » Yes. Waiver order will reset at the start of each new league week (Tuesdays at 6 AM Eastern for NFL, Mondays or Fridays for MLB, NBA, and NHL, depending on your league settings). The waiver order will reset to reverse league rank. League rank is determined by your league's tiebreaker rules. An owner might show a waiver priority of 1, but then drop down in priority if they rise in the rankings during the week.