How do I reset the security context when invoking EJBs from a remote client?

Issue

• A standalone process that calls a secured ejb then a non secured ejb. On the second call, a security context that was initialised during the first call gets propagated. Would like the second call to be made without a security context, in exactly the same way as if the non-secured call was done first. What is the recommended way of resetting the security context so it is not propagated?