That's not unique to just Filipina. Women in general are extremely gullible to those kinds of products. You see the same products in the West.
Show them the ingredients. Let them know they are just rubbing coconuts/mango/avocado/fruit in/on their face/hair/stomach/armpits and then ask them if they thinking rubbing food all over them is going to do what is promised on the bottle.
For a good laugh go find a coconut and rub it all over yourself while they are applying their lotions and let them know your method is just as effective as theirs.....and much cheaper. Proceed to repeat this behavior with any fruit/vegetable you get your hands on.