Org2Org - Delete self register user which are already in Okta workforce

We have Okta workforce and Okta CIAM. Some of the workForce users self register to okta CIAM using the application signup page.Since there was no restrictions on there registration based on email domain.

Currently they are able to login using there workforce account as well as Self register email. Is there anyway there password can be delete from Okta CIAM and then they can only login using there okta workforce credentials.