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Integrative Health

I Thought My Oral Hygiene Was Solid, But This $28 Device Proved Me Wrong

Author: Braelyn Wood

April 06, 2026

mbg Deputy Commerce Editor

By Braelyn Wood

mbg Deputy Commerce Editor

Braelyn Wood is the Deputy Commerce Editor at mindbodygreen. She has a B.S. in journalism from Northwestern University, along with a certificate in marketing.

Image by Jamie Grill Atlas / Stocksy

April 06, 2026

We carefully vet all products and services featured on mindbodygreen using our commerce guidelines. Our selections are never influenced by the commissions earned from our links.

Heart health, gut health, and brain health get a lot of airtime in the wellness conversation, but oral health rarely gets a seat at the table (despite being deeply connected to all three). Research has shown that poor gum health is associated with a higher risk of conditions like heart disease, diabetes, and Alzheimer's.

In other words: What happens in your mouth doesn't stay in your mouth.

So yes, I take my oral health seriously. I floss every night, see my dentist twice a year, and I'm always looking for ways to be more thorough. Earlier this year, I was on the phone with my mom as she was driving home from the dentist when she launched into a cautionary tale that ended with one firm order: Go buy a water flosser.

Her reasoning? They reach areas that even the best string floss cannot. A quick search confirmed it. Studies show water flossers are effective at removing plaque from hard-to-reach areas between teeth, sometimes outperforming traditional floss in those spots.

A few weeks later, as luck would have it, I had the chance to test the Coslus E40 Water Flosser. Here's my honest review after two weeks of nightly use.

Coslus E40 Water Flosser

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What is the Coslus E40 Water Flosser?

The Coslus E40 is a cordless, rechargeable water flosser that uses a pressurized stream of water to clean between teeth and along the gumline. Just like my mom said, it targets the areas that brushing and string flossing often miss.

What sets the Coslus E40 apart from a standard water flosser is its stepless roll dial, which gives you precise, continuous control over water pressure across 10 speeds within each of its two modes.

Think of the stepless roll dial like a dimmer switch versus a standard light switch. Instead of toggling between a handful of preset pressure levels, you can roll the dial smoothly to find your exact preferred pressure and fine-tune it as you go. This makes the Coslus E40 particularly good for sensitive gums, because you can ease into it very gradually rather than jumping between fixed settings.

A few key specs:

- Two modes: Floss and Soft Clean, each with 10 adjustable speeds

- Stepless roll dial: Continuous pressure control rather than fixed settings

- 300ml water tank: Large enough for a full session without refilling

- Five interchangeable tips: 2 standard jet tips, 1 orthodontic tip, 1 periodontal tip, and 1 tongue scraper

- USB rechargeable

- BPA-free

- Price: $28

Image by mbg Creative

The science behind water flossing

Unwilling to go simply off of my mom’s secondhand praise for water flossers, I did a deep dive into the research before trying this one out. The case for water flossers is solid. Studies have shown that water flossers can remove significantly more plaque than string floss alone, particularly along the gumline and in the tight spaces between teeth where traditional floss struggles to reach consistently.

For people with sensitive gums (like myself), water flossers are also gentler than the back-and-forth motion of string floss. I’ve had issues with bleeding gums in the past, so I was happy to learn this before jumping into testing.

How to use the Coslus E40

My favorite products to test are those with absolutely no learning curve, and the Coslus E40 definitely fits the bill. I'm not usually one for instruction manuals, so I was happy to discover how easy this one is to use.

To get started, simply fill the detachable water tank, select your mode and pressure level using the roll dial, place the tip in your mouth angled toward your gumline, and guide the stream along each tooth and into the gaps between them. The brand recommends keeping your mouth mostly closed to avoid making a mess (a tip I admittedly learned the hard way).

It was easy to incorporate into my nightly routine, right after brushing. On my first night, I started on Soft Clean mode at a lower speed and found I was able to work my way up over the first week of testing. Even with sensitive gums, I didn't experience any discomfort.

Image by mbg Creative

My experience after two weeks of testing the Coslus E40

For starters, my mouth genuinely feels cleaner—and I say that as someone who was already pretty diligent about oral hygiene. I can now fully attest to the fact that there’s a thoroughness to water flossing that string flossing alone doesn't quite replicate (at least in my experience).