My stubborn bleach resistant client in Phoenix and the 20 minute olive oil trick

Had a client with level 4 hair that just wouldn't lift past orange, even with a 30 volume developer. I remembered an old tip from a stylist in Scottsdale about pre-treating with pure olive oil for 20 minutes before applying lightener. Tried it, and the lift was way more even and got us to a clean level 8. Anyone else use pre-treatment oils on resistant hair, or is that a bad idea for some hair types?