I cannot speak to the practice in 2018, but earlier in the C Dory history, the factory put one of the Bostek Sealants on the hose barbs. I guess they felt that that give more security on the connection. The standard practice should be double clamp hoses to the thru hull fittings. I don't know how well this material (similar to 3M 4000) sticks to the fittings, or tubing. This is either the same or very similar to the material they used to seal the cabin top to the cabin side walls (as well as one layer of tabbing). The reason I know about this is when I received my Tom Cat 255, there was no caulking between the cabin top and sides. C Dory sent me 9 tubes of this sealant.
An aside, I have had issues with some hose barbs and tubing; for this I used "form a gasket" by Permatex, #2, (non hardening, approved for air craft). This works well in critical conditions, but with heat it will loosen. I am not sure about heat on the material which C Dory used. You may want to contact the factory.