This happened to me often when I go to some restaurants or be on a visit to somebody place. It just happen that I want to add some lemon to my soup or use it as an addition to my meals but they do not have access to a lemon crusher. Is that the name of the tool?.   I've seen people used forks, spoons and just their thumb for squeezing the juice of the lemon. But is there a method which has proven to work the best to take out all of the juice without trying to make much force with the hands or something?. Is there a tool that can be carried on maybe portable for this purposes?. 
Yes. This happens to me. Some scientists are investigating the possibility of using the peppercorns as a means of reducing people's salt intake.  Potential of Szechuan pepper as a saltiness enhancer, Tram Hong Le Bao, Siree Chaiseri and Yaowapa Lorjaroenphon, International Journal of Food Properties 21(1), pp533-545. 