Note to self.
Add the following lines to .bashrc file to clean Gromacs backups :
# clean Gromacs backups in the current directory
alias cleangromacsbackups="rm -f \#*\#"
# clean Gromacs backups recursively (for the fearless warriors)
alias cleangromacsbackups_rec="find ./ -name \#*\# | xargs -r rm"
Be careful with the second command...