As described during my previous post, heres the video of the Blue Helen butterfly squirting.
Here is the side view of the butterfly with its proboscis extended.
Update >> Consult Dr David Lohman today. He described this phenomenon as "puddling", a process where by the butterfly suck up water, filters off the salt and minerals and squirts out the excess water which it drinks. Normally it is the male which does this, as the nutrients are required to make pheromones and sperms. He also told me that people use animal urine and sometimes even their own to attract these butterflies to puddle together!