Sounds like you have a nice crop of 'ornamental' gourds. They might last longer if you keep them out on the porch or in the garage. But, you can bring them in for decorating.....just watch that they don't rot.
As for the shine, a quick, easy thing to do is dip them in floor wax. This will dry faster and be a lot easier than brushing, or spraying with polyureathane. Drain them on some sort of rack over newspaper. Let me know how this works for you.
Jan