Best way to clean carbon off the top of a piston

Hey guys I tore my hemi down last night and after 130k miles she looks pretty good. Bearings are like new cylinder walls are still cross hatched and I will be throwing her back together next weekend but before I do I wanted to clean off my pistons but I haven't had a ton of experience in reusing pistons (normally building for other people and using new parts) Does anyone have a suggestion on what I could use to clean the tops of the pistons? I don't want to use an abrasive and I know there is a ton of build up on these puppies.