Chair Doctor™ glue does exactly what the name implies; it fixes chairs. If a chair has a loose rung, an injection of Chair Doctor glue will first swell the rung and then bond it in position. The secret is the low viscosity. It will soak into the end grain of wood, swell the wood and then freeze the wood in the swollen state as it cures. A film of dry glue lines the wood cells, preventing contraction. The glue can penetrate the narrowest of cracks.
If you happen to leave any excess or spillage, it can be removed with a damp cloth. Any missed on a surface will dry clear. Chair Doctor Pro includes 115mL of glue, 1 syringe, and 3 sizes of blunt-tip needles. Usually, you let Chair Doctor glue seep into a loose joint, but for many loose joints you can actually slip the finest needle alongside the tenon to the base of the socket, then inject it full of glue.
For very difficult repairs, you can drill a tiny hole (from below or behind) and inject glue into a joint that way. With a syringe, it is very easy to do a large number of joints quickly and neatly. Even better, everything cleans with just water so the needles and syringe are reusable indefinitely.