How to Use the COSLUS E40 Water Flosser

The COSLUS E40 is designed to give you more control over water pressure without making the routine complicated.

To use it, fill the reservoir, choose your tip, place the tip in your mouth, start at a comfortable pressure, and guide the water slowly along the gumline and between your teeth.

If you are new to water flossing, begin gently. You can increase the pressure as you become more comfortable.

Before You Start

Fill the 300mL reservoir with clean, lukewarm water.

Avoid very hot water. Lukewarm water is usually more comfortable, especially if your teeth or gums are sensitive.

Next, insert the tip that matches what you want to clean.

For everyday use, the standard jet tip is usually the simplest choice.

E40 also includes specialty tips for different needs, including:

• Orthodontic cleaning around braces
• Targeted periodontal areas
• Tongue cleaning

Make sure the tip is securely attached before starting.

How to Use the E40 Step by Step

Simple From Day One

Fill. Dial. Floss.

The E40 is designed to make personalized pressure feel intuitive—even if it’s your first water flosser.

1

Fill the 300mL tank

Use clean, lukewarm water and close the reservoir securely.

2

Start at a gentle level

Place the tip in your mouth first, then turn the unit on and adjust the pressure.

3

Guide along the gumline

Lean over the sink and move slowly from tooth to tooth.

1. Place the Tip in Your Mouth

Do this before turning the water on.

Lean slightly over the sink and keep your lips loosely closed around the tip. This lets the water flow naturally into the sink instead of spraying around the bathroom.

2. Start at a Comfortable Pressure

Turn the E40 on and begin at a gentle setting.

The E40 uses a 10-level pressure dial, so you can make smaller adjustments instead of jumping between only a few preset intensities.

Increase the pressure gradually until the stream feels effective but still comfortable.

Higher pressure is not automatically better. The goal is to find a level you can control easily.

3. Aim Along the Gumline

Position the stream close to the gumline and guide it slowly from tooth to tooth.

For general cleaning, aim approximately toward the area where the teeth and gums meet.

Pause briefly between neighboring teeth before moving on.

A simple route is:

back tooth → gumline → between teeth → next tooth

Working in the same order each time makes it less likely that you will skip an area.

4. Clean the Whole Mouth

Continue around the upper and lower teeth, including the inside surfaces.

Do not focus only on the front teeth. The back molars are often where food is easiest to miss.

You can divide the mouth into sections and finish one area before moving to the next.

There is no need to hold the stream on one tooth for a long time. Slow, steady movement is usually easier to control.

Floss Mode vs Massage Mode

The E40 has two water-flow modes: Floss and Massage.

Floss Mode

Floss Mode is the primary option for everyday water flossing.

Use it when you want to clean:

• Between teeth
• Along the gumline
• Around areas where food tends to collect
• Around braces when using the appropriate tip

Massage Mode

Massage Mode changes the water-flow pattern to create a more pulsing sensation.

It can still be used while cleaning, but its main difference is the rhythmic water pattern and gum-stimulation experience.

Think of it this way:

Floss Mode = focused everyday cleaning

Massage Mode = pulsing cleaning with gum massage

Pressure can still be adjusted separately, so Massage Mode should not be confused with a dedicated “low-pressure” or “sensitive gums” setting.

How Long Should You Water Floss?

For most users, about one minute is enough for a full-mouth water-flossing session.

A simple way to pace yourself is to spend about 30 seconds on each arch, moving steadily along the gumline and pausing briefly between teeth.

You do not need to hold the water stream on one area for a long time. Once you have worked systematically around the upper and lower teeth, the session is usually complete.

If you wear braces or have areas that need extra attention, you may spend a little longer on those spots—but longer is not automatically better.

After You Finish

Turn the E40 off before removing the tip from your mouth.

Then:

• Pour out any remaining water.
• Rinse the reservoir if needed.
• Remove and rinse the nozzle.
• Allow wet parts to air-dry.

Simple maintenance after use helps keep the water-contact areas clean and ready for the next session.

Common Mistakes to Avoid

Starting at Maximum Pressure

More pressure does not automatically mean better cleaning.

Start lower and adjust upward only when needed.

Turning It On Before the Tip Is in Your Mouth

This is the fastest way to spray water across the sink or mirror.

Tip in first. Power on second.

Moving Too Fast

Give the stream enough time to reach the gumline and spaces between teeth.

Cleaning Only the Front Surfaces

Remember the inside surfaces and back teeth.

Using Massage Mode as a Substitute for Pressure Adjustment

Massage Mode changes the water-flow pattern. If the stream feels too strong, lower the pressure with the dial.

The Bottom Line

Using the COSLUS E40 comes down to a simple routine:

Fill the tank. Choose your tip. Start gently. Follow the gumline. Adjust the pressure until it feels right.

Use Floss Mode for everyday cleaning and Massage Mode when you want a pulsing cleaning and gum-massage experience.

The E40's main advantage is that you do not have to settle for only a few pressure presets. Its 10-level dial gives you more room to find a setting that works comfortably for your routine.