Honda sells some stuff called "Top End Cleaner" that basically gets sucked thru a vac line like 1stGen said. It comes in a can and is like $4 per can. The cans are kinda funky, so you need an iduction tool that's like $30 to use em. The part numbers for the cleaner and tool are 08732-9008 and 08732-9010 respectively, but I would just use some water or ATF. The key is small amounts at a time sucked thru one of the vac lines on the intake manifold.