The second one is something you can do if you are willing to do it when you build/renovate a house and it would not be hard to build if you don’t mind a project… Get a compressor, a long hose to run through the walls next to the water pipes, and plug the hose to a nozzle. If you feel fancy and have enough money hire a machinist (or make it if you have the skills and access to the equipment) to make a custom drying tool with a wide and thin nozzle for the compressed air to reach your body, and a handle to turn it up and down. This would allow you to dry your body in seconds.

It doesn’t fit the “instantly” if even a few seconds is too much, but if you really want to do it as close to instantly as possible, a nuclear bomb will definitely evaporate the water on your skin within a millisecond… along with everything else.