You don't want to keep your record by any chances. Then you can simply remove or delete all your search data from Facebook easily. That keeps you safe and there will be no chance that anyway to find out your history of search.
Follow the below steps to delete all your search data history:
Step 1: Go to your timeline profile and click on "Activity Log".
Step 2: On the left side menu bar click on "More" under the photos likes and comments.
Step 4: Now a list will appear with all your Facebook search history in date order from Today till the starting. To delete all the search history just click "Clear Searches".
Step 5: Confirm that you want to clear all your search history by clicking on "Clear Searches".