Delete a subform entry by clearing the Parent ID Relationship field

Delete a subform entry by clearing the Parent ID Relationship field

Hi

I have my subform form with an existing relationship field showing so i can see the parent form ID which is written every time a subform entry is made from the main form

Can I and is it safe to delete main subform entries by writing a null to this field.
This would give me a way programmaticly remove subform entries.
(in may case delete a booking record if date expired and deposit not received)

While i am thinking about it, is it safe and smart to programmaticly add entries to the subform form by adding an entry and making sure i insert the correct ID into existing relationship field

thanks