Hello Sir or Madam. Welcome to justanswer!
Yes its a blow through coil. They sell solvents and kits for cleaning it without causing any corrosion. Its available at almost all auto parts stores.
with out removing it? is it a spray on type ?
Thats correct it comes with a tube and cleaner that you use to apply the cleaner without taking it apart all the way. Below is a link to a website that sells it.