Yes. While you can clean every room in your home with vinegar and baking soda, you should not use them on marble floors. Vinegar is too acidic, and baking soda is too alkaline; both of them can lead to etching on your marble. A pH-neutral cleaner is your best bet to clean marble floors.

The best thing with which to clean a hot tub is whatever the manufacturer recommends; in most cases, this is a gentle surface cleaner and a soft cloth. Recommended hot tub cleaners can include specially formulated cleaning agents, mild dish soap, baking soda, vinegar, or diluted bleach. For your hot tub exterior, choose wood or vinyl cleaner (depending on the casing material).

You should never use household cleaning products, harsh chemicals such as undiluted bleach or acids, or abrasive cleansers or cloths, as these can scratch or etch your hot tub’s coating or shell and cause permanent damage.

You can always use a homemade vinegar solution as a natural alternative to commercial cleaning products. To make and use a vinegar cleaning solution, fill a spray bottle with equal parts white distilled vinegar and warm water. Spray the solution liberally across the tub surface. Let it sit for 10 to 15 minutes before wiping it down with a non-abrasive sponge or cleaning cloth, then rinse with clean water. If a line of soap scum is still visible, spray it with the vinegar solution. Use a soft-bristle toothbrush to gently scrub the residue away before wiping it down and rinsing again.

Yes, if you’re strapped for supplies, boiling hot water can be a great alternative for getting rid of soap scum. However, as this method calls for a bit of soaking, it’s best used when cleaning your bathroom sink or bath basin (or on small objects you can submerge). All you have to do is plug your sink or bathtub drain and pour in enough boiling water to cover the soap scum. Allow it to soak for five minutes, drain, and follow up with an additional hot water rinse to remove any lingering residue.