Now we can put together a fixture to let the Sugru dry in. I used a C-Clamp, some scrap wood, and a foam pad to compress the watch.

The wood helps distribute the clamp force evenly across the display, and the foam helps protect the glass.

Make a Pebble sandwich with the clamp, wood, foam, and watch. Tighten the clamp enough that the watch is compressed, but don't make it too tight.

Remove any more Sugru that seeps out with a cotton swab.