I have a typical cast iron top mount sink on a laminate countertop. The caulk around it seems to be deteriorating and if I look under the sink I can see some discoloration in the particle board in spots. I guess that means water is getting under there. I'm wondering if it would be better to pull the sink completely out, clean up any old caulk, and apply a bead of fresh silicone (that's what I should be using, right)?

Or can I get away with just cleaning up what's visible and maybe running something like a utility knife blade or scraper under the rim of the sink to remove what I can. Then apply a fresh bead of caulk along the edge???

Thnx!