There is an option in the Directional Scanner settings that tells it only to report the same classes of items as currently selected in the active Overview. That is very good for decluttering the d-scan, but does require you to set up the overview correctly.
However, small items such as wrecks, will not appear on the D-scanner whatever the settings - it is designed to detect ships, not lumps of cold debris. Nor can scan probes detect them. The nearest way to finding wrecks is to look for the mission runner’s ship while he is still in the mission (using scan probes) and go in afterwards to clean up. Being aware of course that looting his wrecks rather than just salvaging will give you a timer during which the loot owner can attack you.
Alternatively, ask if someone would be happy with you tagging along as they rat or mission run clearing the wrecks for them. I’ve had people do that for me in the past - either gratis or for a small consideration.