I use a gourd canteen and my son uses a gourd water bottle when out trekking, we make our own so I thought I'd share how I make them for us and friends.
The type of gourds that were most used for lasting containers were of the type Lagenaria whose white blossoms open towards evening and grow on aggressive vines. They require a long growing season to mature and are extremely cold sensitive. They are mostly light green with sometimes some white mottling, never brightly colored. They have a woody sub-surface that can range from 1/8 to 3/4 inches in thickness. When the gourd is in the green condition it is fragile but as it cures (which can take upwards of two years) the woody sub surface matures into a very hard and durable material. It is my experience that the slowest curing process is the best, although the most messy. I have heard all types of instructions from all over the country on how to cure them fast. I have never had success in coming up with a durable container by any of these methods. The green and fully mature gourds are picked after a growing season of between 120 and 150 days. Now begins the long curing process. I will wash them down to remove any dirt that may be attached to them and then they are spread out (so they don't touch each other) on newspaper in a warm dry place like an attic, loft or in the basement near a heat source. They can be left outside if they won't freeze but I have always had problems with animals stealing them to get the seeds during the winter months and up north they are far too precious to lose any to forest critters. They should be turned often, at least once a week. During the curing process they will develop a heavy mold which is normal and this will not cause them to rot. If the gourds are to be used for something other than food or drink containers they could be wiped down every two weeks with a solution of a bit of disinfectant liquid in some warm water to retard mold growth, since the mold has a tendency to discolor the outer surfaces. THIS SHOULD NOT BE DONE FOR FOOD OR DRINKING CONTAINERS! The mold is a natural process and although it looks horrible it is very natural and harmless. I have to admit that they start looking pretty funky about three to four months into the drying /curing process but I don't believe I've ever had them smell worse than a fresh mushroom. They have very little flesh inside so they wont spoil like a pumpkin or the like. Actually, if they were on the vine a long enough time they may even feel lighter than you would think, because some of the curing had begun outside at the end of their growing season. These lighter ones will cure the fastest but sometimes their shells are too thin and will collapse. This was not due to the molding. They were destined for failure from the start: they never matured to begin with. The very heavy ones may take up to two years to dry and cure.
When the curing process is complete you will notice that the gourd is now light in weight, the mold has dried to dust coating ( I must mention here that mold spores and dust can affect sensitive individuals so please take care) and many times the seeds will rattle inside.
Select a cured gourd by the firmness of the shell. A good shell is at least 1/4 inch in thickness and shows no signs of collapse.
The dried and cured gourd is soaked in water or a cloth is applied to its surface, warm water is placed over the cloth and remains that way until the dry skin can be easily scraped off with a dull knife. This may take some time. This exposes the hard wood shell. Let the gourd dry for a couple of hours after scraping. Now, depending on what type of gourd you have, you will either saw off the tip (as in a water bottle style) or drill a sizeable hole in the side (as in the case of a tobacco box style). Make the hole the size of the cork you intend to use.( I have found a 3/4 in. hole is adequate for a small bottle). This is achieved by sawing (use a fine tooth saw such as a hacksaw ) the top off about 1/2 in. down. The tobacco box can have a smaller 5/8 inch hole drilled in its side for the cork.