For a good joint, a fluted or spiraled dowel must fit snugly enough in the hole to allow the glue to come up around it. The dowel should reach to the bottom of the hole and be used with enough glue. For insurance, apply glue to both the sides of the hole and to the dowel itself.
You can extend the the time it takes hot-melt glue to set by slightly pre-warming both the surfaces to be joined with a heat gun. A heat gun also works great for stripping paint and other odd jobs. For example, you can use it to remove bumper stickers, defrost freezers, char-stain wood, dry wood for painting, burn weeds from cracks in sidewalks and patios, light charcoal, loosen rusted bolt nuts and bend certain plastic piping.