Then follow the instructions in this video to obtain a serious sucking effect with the Fleshlight.
This technique can also be used for a good pressure effect as well. All you need is a container with the right dimensions such as a mason jar or something similar, with a mouth of about 2 to 2.5 inches diameter.
WARNING! Be careful as this can possibly be dangerous, dealing with the pressures and vacuums involved. I cannot and will not be held responsible or liable for anything that may occur to you or anyone else as a result of watching or not watching this video.