butter someone up —(coll.) flatter a person in order to get him to do smth.:
- No, I am not trying to butter up the professor who is going to grade me on this.
oil someone up—
1. (Austral. sl.) advise a person; give smb. reliable information:
- Don’t worry, I’ll oil him up on what needs to be done.
2. = butter someone up:
- He had been chosen because of his power in the Senate. Kennedy oiled him up and convinced him he’d be even more powerful as Vice-President.
Note: The expression does not correlate in meaning with the phrase grease someone’s palm (sl.)—pay or bribe a person for a special favor:
- We had to grease the palm of the waiter to get a table in the crowded restaurant.