when you buy them at the Asian stores.
If they are frozen, thaw them out in the fridge overnight
before you can clean them.
Rub really well the inside and outside of the fish with salt
or baking soda to get rid of the slimy-ness and fishy smell.
Rinse fish good with cold water.
Using a very sharp knife, make a couple of gashes
diagonally across both sides of fish.
Drain on paper towel.
Sprinkle plain salt or garlic salt all over the fish,
inside and on the skin.
You can tell that a non-Filipino gutted and scaled the fish as the heads and tails had been chopped off. I think the fish look more like snakes without the heads on than they do fish. That is probably the reason most Filipinos including myself like to keep the head intact even though we don't usually eat that part of the fish.
How to fry fish:
Fry fish about 8-12 minutes on one side turning just once. The other side should not take as long. Remember, this is whole fish, so it takes a little longer to fry than fillets do. Also, cooking time varies according to the size of fish.
If you want the skin of fish to be soft, put a lid on while frying. If you want the skin to be a little crispy (but not burnt) or nice crust, do not put lid on, just place oil splatter screen on the pan.
(My) rule of thumb when frying fish: when the sizzling sound starts to die down or subside, it's time to flip the fish and fry the other side. I learned this trick from my mother who was born and raised in Binmaley, a town in Pangasinan where there are fish ponds all over the place. There is no science to this but it works for me all the time.