If for some reason, you want to delete many objects (say many Participants, or Specimens, etc), you can do it via CSV import.
Be very careful since deleted objects cannot be reverted back.
Tips to perform large bulk imports
Perform such import during off-peak hours. You can enable the 'System Lockdown' feature to stop other users from logging into the system.
Delete objects which have many dependent obects can take long time.
The database locks the tables from which the data is being deleted. Set the pre-validate to a small number 100 or 200 to ensure the locks are not held for a long time.