The "qxlogin" shortcut doesn't exist anymore, I've suggested that CRC should re-implement that convenience. Nevertheless, interactive seesions can be had. Riley Epperson kindly provided this information.
Interactive jobs can be run on any nodes. Those queues are nodes that the owner groups purchased.
The new command would be:
msub -X -I -lnodes=1:ppn=1
That will run in your default queue, which is displayed with 'mystats'. If you wish to run on a node that is not in your owner group, like a GPGPU node, you will then need to specify the sixhour queue and the node name. You will only have a maximum of 6 hours on this node. There is no time limit to your default queue.
That command would be:
msub -X -I -lnodes=g005:ppn=1 -q sixhour
CRC made a page regarding queues at http://crc.ku.edu/queues