Gami recommends Hoppes, see attachment. TCM suggests some other things, mostly flammable, like MEK. As the son of a clockmaker I can say brass parts are safely cleaned in non-flammable clock cleaning solution and rinsed in alcohol to remove traces of film and water.
I went a third direction and used 1cup hot water, 1/4cup vinegar, dash salt, dash of liquid soap. Works in seconds in the ultrasonic. [Do not dump the residue in a white sink].
After cleaning and replacing all six injectors, my takeoff fuel flow jumped 2gph.