This is an oldie but a goodie. Add 1/2 cup of corn starch with 1/4 cup of water. Mix until substance is consistent You'll need an amped speaker. I used an 8 inch amped sub.
You'll need to generate a Sine Wave. You can download free programs that
can make a Sine Wave. I used 60HZ. I used red food coloring at the
end. It may take a little trial and error but it's worth it. :D Good
luck!