All you need is:
An empty bottle (I used an old water bottle)
Canola oil (original post says any oil will do but I decided to stick with what she used)
Pour in two-thirds of oil and one-third of water into the empty bottle, leaving an inch at the top.
Next, pour in 10 drops of food coloring:
And finally, crush up an Alka-Seltzer and drop pieces in. And voila! You're done!
...still don't believe this works? Watch the video below - after 1 minute, I drop in a bigger piece and it really starts to go! Note: no cats were harmed in the making of this video:
TOTAL COST: Free!
Assuming you have an empty bottle, oil, food coloring and Alka-Seltzer at home
TOTAL AMOUNT OF TIME: 5 minutes or less
EASY-PEASY SCALE (1 super easy - 5 very difficult): 1 out of 5
This would be a great experiment for kids or for the kid at heart!