Here is a short video demo of fixing accordion reeds with wax. The wax is a mixture of rosin, which makes it very sticky, and beeswax, plus some other ingredients. I have tried making reed wax, with variable success. But nothing compares to the genuine Italian made stuff. They must have a secret recipe.
There are a variety of ways to apply the wax, but this is the way they do it in the Italian accordion factories, and I find it the easiest way.
It takes a lot of practice to get the wax where you want it! It’s easy to undo work by getting it on the reed tongues.