I use a single line attached in the middle with a butterfly knot to a chain hook. I hook the chain, then tie one end of the line to each of the bow cleats, tying everything on the outside of all the gear and ignoring the anchor roller completely. It works ok, but since I have a very plumb bow, the chain/hook sometimes hits the bow and I really dislike that. If on the other hand I tie a single line with a chain hook, and lay it down alongside the chain, on the roller, I don't have that problem, but then I can't bring the snubber to one of the cleats with a fairlead, without chafing against the anchor roller edges or looping around the windlass (which defeats the purpose of avoiding the brunt of the stress on the windlass).
Any better ideas? If I had a cleat or a chain stopper right behind the windlass in line with the chain direction it would work better. A much longer line using the two cleats might work fine? Chafe protection instead?
The image below (very similar to my boat) may help understand my description better, note the cleat, roller and windlass positions.