That's pretty much what pimple popping is for sure! And no it doesn't make the underlying pimple go away immediately.

A white head is where you have a blocked pore and some bacteria in the oil inside the pore. Your bodies natural defense against these bacteria is to send in leukocytes which kill the bacteria but then die themselves forming the 'white stuff'. If left alone your body will eventually resorb the white stuff. When you pop the pimple you clear the white stuff out but leave a small wound and the tissue in and around the pore is usually still inflamed and needs a little time to recover and regenerate to a normal state and can be vulnerable to re-infection while that is going on. Don't know if that helps?