I'm just gonna post my 2c here, even though I have nothing to do with this league...

If the last-place team gets first waiver priority for the week, and that person acquires someone on waivers:

1) ...and beat someone else who wanted the same particular free agent, then that team should be set to the end of the waiver wire priority list for that week.

2) ...and was the only one to choose a particular free agent, should regain his 1st waiver priority status.

I believe that's how it's always worked in all sports/leagues, and that's how you should do it here.

I see no reason why the last-place team should get 7 days of potentially stealing free agents from the rest of the league. He should "win" over another, and then drop down to the end - and/or - acquire a free agent on his own without being penalized his priority status.