I was recently drug tested while I was high on opiates. It was a mouth swab test. I didn't rub the swab against the inside of my cheek or get it wet with my saliva very much. Is it possible to pass since the swab wasn't vigorously rubbed against the inside of my cheek (which would transfer the cells onto the swab)?d

It might just come back inconclusive if you did it improperly. But yes, it will test positive if you used that day.

You say you didn't get it wet too much with your saliva. It doesn't matter if you got one drop of saliva or a whole bunch. Either way it will register on the test. Any drug that is smoked like pot or meth gets "stuck" in your inner cheeks and stays there. That's why they switched to cheek swabs. Cheaper, too.