fsl_sub doesn't clean up wrapper_<jobid>.sh scripts
The default behaviour should be to clean up the wrapper files (as specified by the --keep_jobscript option). However the wrapper is left behind regardless of whether this option is set.
version info: fsl_sub 2.5.3 (fsl_sub_plugin_sge 1.4.5)
I made a tiny example here: /home/fs0/edmond/scratch/Public/test_fslsub_cleanup