There are two ways you can clear an EJB object reference.
EJB builder nameClearRemoteReference
This method sets the EJB LJO variable reference in the WebApp to null, which will force the EJB builder to recreate the EJB remote reference. This technique might be useful if you want to use a single EJB builder to reference multiple entity EJBs. EJB builder nameUtil.flushHomeCache
In this case you can specify a finder method which takes a variable as the input to the finder method, then when you want to reference the EJB set the variable to the appropriate value and call the xxxClearRemoteReference method before calling methods on the EJB remote variable.
This is the utility class created by each EJB builder. This class is hidden in the method chooser widget in the builder call UI, but you can access the webAppAccess.getVariables().getObject()
Parent topic: EJB Call builder: wpf7