Here's a link to a CRL sealant Amazon sells:
CRLAURENCE777BLCRLBlack777ButylRubberSealant -...
The stuff in the pint can flows more easily, and that's what I used when I was doing windshields years ago, but it requires an applicator that's similar to an oil can gun. The caulk tube is a little stiffer composition, but it should work for you.