Combine all of the ingredients in the bottle, pouring in the vinegar last. Depending on the exact size of your bottle and sprayer you may not need all of the vinegar. Be sure to leave a little room at the top to allow for mixing.
Shake well to combine and before each use.
Notes
To use: Spray liberally on bathtub and shower surfaces, avoiding any metal fixtures. Scrub off with a microfiber cloth or sponge.