So I've been enjoying the enthusiasm of Clicker trained dogs.

Now I'm wondering how I can add a remote Down via a raised hand signal in case I need to have him hunker down in an emergency.

The more traditional approach is to be close to dog, give the cue and lure with treat, to get the down. Then gradually work on increasing distance once the near down is established via hand signal. As I have the down behaviour established, I guess I can add the cue right away, and gradually increase distance.

Any tips for when to phase out the clicking on this?

I have done some distance control work, mixing it in with play which became self rewarding, so I don't have to try and accurately project treats 30m or so. I saw something about remote clicking in another thread, so I'd like to benefit from other's experience on this.