At the end of a shutdown purge, we recommend running the system empty before you cut the heats and go home. This is as opposed to leaving the barrel full of purging compound.
There are folks who are concerned that this will leave the metal surfaces inside the barrel vulnerable to corrosion but that's not the case. Those metal surfaces will still be coated and "sealed" by a protective layer of purging material.
The advantage to be gained from this procedure is that you’ll save time at startup. The system will get up to operating temperature more quickly when you don’t need to heat and re-melt a full barrel of material.