I was asked my thoughts/experience on making your own gourd rattle.
The best practice is to grow your own gourd which is, by the way, one of the easiest of all plants to grow. Absolutely nothing needs to be done with the vine in the ground after they are planted. Just leave them alone and water if it gets to be too dry of a summer (down here in Florida I had to water mine frequently). I actually grew them last year in a sunken hot tub shell to assist with the no weeding option.
If you are growing your own, leave the gourds on the vine until they dry themselves. No need to interfere with what nature has been doing all by itself for centuries. With the assumption that you are not growing your own, try to purchase your gourds from a local organic farmer. You want a gourd that has a stem that is perhaps 3-4 inches long if possible.
The best results I have found is to wash the gourd in a solution of bleach water (1 part bleach to 5 parts water) which sterilizes the gourd and removes anything on the surface. It seems to help with preventing rotting. The next step is drying the gourds. The best idea is to have a location outside with plenty of air flow. The most vital aspect of drying is air flow.
The drying or curing process can create an offensive odor as times goes, so you really do want to keep them outside for this process. Don't worry if the gourds develop a mold on the outside. This is not indicative of rot. The mold actually can create some of the most artistic patterns on the gourd itself and can be easily wiped away once it is completely cured.
When you are using a natural process to dry you will invariably have some that will rot. It just is part of nature. Be sure that as you lay the gourds out that none of them touch one another as this will only encourage decay. If you find some that have that soft indentation forming, throw them out. They will not harden up.
Realize that most gourds are primarily water; thus patience is a must. It can take up to six months to naturally dry themselves out. When they are completely dry they will have lost up to 70% of their weight and will have the natural rattle from the seeds inside of them.
If you want to dry them naturally and are in a bit more of a rush, you can poke holes in the gourd (the large round side) and hang them upside down (holes facing down) to dry. Remember that they are primarily water based. It will make a mess as the initial water drips out.
Is there a faster way? I have been asked this many times. Yes but can not always guarantee results. You can purchase a gourd at a farmers market or organic farm. Cut off the small end of the gourd and scrape out the insides with a spoon, keeping the seeds to go inside the rattle. This rapidly will speed up the drying process. You still need to set the gourd out for drying but the time can be weeks rather than months (9-12 weeks). If it is a small enough guard you can also dry the gourd in a convection oven on low. The temperature has to remain constant. another method is to bring water to a boil and simmer the gourd for about 30 minutes before carefully placing it in a well ventilated area that gets sun to dry. This is the method I have used if making a bowl from the gourd especially.
I prefer the old fashioned method of letting them dry themselves. If you used the natural method, simply decorate and shellac to preserve the finish.
If you cut the stem off, you will need to make a handle. Find a piece of willow branch or cotton wood (dowel if neither is available) and glue it securely with either white glue or a hot glue gun. Mix white glue and sawdust together into a paste and apply it to where the handle and gourd come together. Allow this to dry completely and then you can sand the joint so that it is smooth to touch.
The interesting part of using this method is to experiment with different seeds, beans, or small pebbles for different sounds to the rattle. Decorate and shellac to preserve.
Hope this gives you some ideas in making your own gourd rattles. Happy shakin!