Brad, who works in the trade of caullking high rise buildings, sent in the tip of dipping a shaped piece of wood into Sunlight detergent before tooling the caulking. This gives the caulking the exact shape you want, but nothing sticks to the wooden tool. Note that his tool is not curved. For details on techniques for tooling caulking check out this animation. For details on caulking types, click here.
Then we looked at a gadget that is available in most hardware stores. It is simply a split guide that goes on the end of the caulking gun. This will straddle boards such floor joists and guide the caulking or adhesive in a nice straight line down the centre of the board. "Guiding Tip" from CG Tips. I wrote that in 2001 and in 2014 I can't find this great little gadget. If anyone knows where to find it or anything as simple for drawing a straight line of adhesive on a floor joist, let me know.