Personally I've had much lesser delays/stalls using this command:

ALTER DATABASE SQLTRIX SET OFFLINE WITH ROLLBACK_IMMEDIATE;

And you can get into devilish issues with "SINGLE_USER". You need to make sure you are in the db, sometimes the single_user takes SQL a while to "disassociate". Also a real pain if some other task happens to jump in ahead of you in getting to the db and it becomes the single user, and you're totally locked out of the db.