I'm not sure about the safety of the issue.
To avoid diluting it every time, you could fill a small bottle with carrier oil and add a small amount of the EO, so that you have a decent amount premixed. You could also fill a spray bottle with water, add a little EO and spritz your hair for the scent (shake well before spraying to mix the EO with the water - it will float on top on its own.)
Given both that the scent of EOs is quite strong, and that they are expensive, figuring a way to stretch the oil can't be a bad idea.
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