From the game manual:
Multiple Teams
It is against BuzzerBeater rules to own or operate more than one team or account for any circumstances. We have sophisticated tools for detecting this, and when you are caught, all of your accounts will be permanently banned without warning. You are not allowed to sign up for a second team while you have access to another team.
The underlined implies that once you don't have access to another account, you are able to sign up for a new one. Hence, once you go bot, you can create a new account.
Also from the game manual:
If you drop below -$500k, you must get out of debt within two weeks or you will be fired as general manager because the team goes bankrupt.
So if you don't want to wait 6 weeks, you can buy one of the salary monsters off the TL for cheap and go bankrupt quicker.
Rather than buying a salary monster, it's easier to get lvl 7 trainer with ridiculously high salary. Only a handful of people buy trainers who are like $150k every week. But yes you could also buy salary monsters to go in debt quickly.