Depends on how large the % is. I have a ton of money so when a boycott hits, I start at 30% and it only works down 3% per week, so it takes a full season! If you are still doing poorly, it will reset too during the current one. It was put in place to prevent people like me from tanking hard and collecting cash. And it works. It will stay with you even when you are doing well the following season, etc.
Of course, If you don't have a lot of money, the % is less and so you can get rid of it fast.