I use Berryman's Chem Dip. Remove intercooler from vehicle. Pour it in until the intercooler is about 1/2 full, then cap then end tanks with plastic bags and big rubber bands. Slosh it around for at least a few minutes, let it sit for 15 minutes, then slosh around again for a few minutes. Rinse with hot water. My intercoolers end up looking shiny-new inside when done.