Witchhazel & dishwashing liquid - 1 to 3 ratio. Just spray on lightly and wipe off. You can get fancy and use rowan wood and red thread, but finding rowan in this country is a chore. Alternatively, put your clothes on inside out to render yourself invisible to the fae. Also invisible to a lot of other people who are going to be too polite to mention your sartorial choices.

Hey cool! Looks like an album cover!

If no one believes in fairies, they cease to exist.

Mix equal parts vinegar and water, add an iron ingot and steep under the full moon.

Using this may trigger combat so keep a thorn in your pocket