I agree with you, olive oil is not an effective mite treatment. .
I wasn't relay suggesting olive oil as an effective mite treatment, just as a test for new snakes to see if there are mites. a little olive oil helps them come off in the paper towel so you can see if there is a problem that needs treating.
Like i said in the first post, if there were mites detected by that process I would then move on to to other more effective treatments.
If not I would just treat the housing before use (and not the snake) as a quarantine precaution for mite eggs.
Also to others yes agreed keep away from petroleum products