Dave you were right. I tried several items including WD40, oil, & acetone. None of them did much good. I finally used my Dremel with a brush and got the plastic out of the cavities. They were so rough that after I tried a couple of pours, I deep sixed it and have started all over.
This 3 day event was only supposed to take an hour or so. I sure am glad that I am between jobs and don't have anywhere special to go.