init / configスクリプトを実行せずにbashを実行する方法は？

bash --noprofile

構成スクリプト（ユーザーの範囲とシステムの範囲）をロードせずにBashシェルを実行します。

からman bash：

   -i        If the -i option is present, the shell is interactive.
   -l        Make bash act as if it had been invoked as a login shell (see INVOCATION below).

(...)

   --noprofile
          Do  not  read  either  the  system-wide  startup  file  /etc/profile  or  any  of  the  personal initialization files ~/.bash_profile,
          ~/.bash_login, or ~/.profile.  By default, bash reads these files when it is invoked as a login shell (see INVOCATION below).