Go to your kitchen. Find a kettle, fill it with tap water, and set it on the stove to boil [medium heat, works for most]. While you're waiting for that, find a wisk. Using the passive ingenuity inherent in humans, tape/bolt/weld the wisk to some improvised frame so the wires are in the direct line of fire of the kettle's spout [with wisk handle pointing upward]. Put a cup, or if that's too high, a bowl, beneath the wisk wires. Careful you set it so it doesn't melt/ignite.
There you go. Once the water starts boiling, hot evaporated water, also known as steam, will shoot from the kettle tip into the wisk, where the hot steam will condense onto the cool wires. Drops of water will form, run to the bottom of the wisk and drip into the cup/bowl. This water, assuming the wisk and bowl are clean, is pure dihydrogen monoxide, H2O. All the fluoride and dirt stays in the kettle, since they have much higher boiling points.
It'll take a while for the drips to amount to a glassful, but once you set it up, you can pretty much leave it to run.
Don't burn your house down.