Force Termination of User Session - Best Practice?

We occassionally need to terminate user sessions to go "exclusive" on a project or for a rebuild or other emergent maintenance and the user is not available to logoff.  We run the following sql to "kill" the user session and have experienced no problems, but consultants have advised us that this approach can cause unanticipated problems.

UPDATE USESSION
SET DELETE_SESSION_ID = 0
WHERE (USER_ID =
      (SELECT USER_ID AS EXPR1
       FROM USERS
       WHERE (UPPER(USER_NAME) = UPPER(:USERID))))

What are the potential negative impacts of this approach, if any?

Is there a utility or other method available that avoids these pitfalls?