Obfuscating Data Ingested Using Fabric On-Premise Gateway

Hi All, 

I have the below requirement and unsure how to achieve it - any ideas?

I need to obfuscate data to ensure no PII is held within Fabric at all - data will be ingested in pipelines/notebooks from APIs and an on-premise data gateway. I've written a notebook that obfuscates data ingested into a data frame (hasn't been written to a table or file) but there are concerns that this is still held in Microsoft Fabric memory. The business also wants to use lakehouses only, no warehouses. 

Are there any other ways I can achieve this?