I stuck some rolled-up paper towel in there to block any of this crud from getting in the cylinder, then used compressed air to blow it out of there, but that crud is stuck to the surface right around the rim of the port. Short of wetting a paper towel with Simple Green, wiping it free and hoping that the crud sticks to the paper towel rather than falling down into the cylinder, is there any other, better way of cleaning up these ports? I don't see how I can prevent at least a little bit of residue from falling down in there.
Thanks for any suggestions...
MH