Here's what I do
For draining seacocks, I run the pink stuff down their hoses, then close the seacock. This gets antifreeze in the inner cavities of the seacocks. I don't worry about the exterior of the seacock, since ice has room to expand there. For intake seacocks, I close the seacock, then disconnect the hose leading to the seacock and drain it as much as possible, fill the hose with antifreeze and use some sort of air pressure (blowing into it or using a turkey baster bulb) to force some antifreeze out in order for antifreeze to go into the internal cavities of the seacock. I've stored my boat wet for 5 years now (including the winter of the century) and haven't had any problems.
