Proper cleaning and maintenance of your eco-friendly insulated cup is important to ensure that it remains hygienic and in good condition. 

Here are some tips on how to clean and maintain your eco-friendly stainless steel mug:

1. Hand wash your cup: Most eco-friendly stainless steel water bottle are not dishwasher safe and should be hand washed with warm water and mild soap. 

2. Use a soft-bristled brush to clean the inside of the stainless steel vacuum flask, especially if it has a narrow opening.

3. Rinse thoroughly: After washing, make sure to rinse your vacuum mug thoroughly to ensure that there is no soap residue left behind.

4. Dry thoroughly: Allow your stainless steel tumbler to air dry completely before storing it. Do not use a cloth or paper towel to dry the insulated water bottles as it can leave lint or fibers behind.

5. Avoid abrasive cleaners: Do not use abrasive cleaners or scrubbers on your eco-friendly stainless steel coffee mug as they can scratch the surface and damage the insulation.

6. Store properly: Store your double wall stainless steel insulated water bottle in a clean, dry place and avoid storing it in direct sunlight or extreme heat.

7. Check for damage: Regularly inspect your water bottle stainless steel for any signs of damage, such as cracks or chips. If you notice any damage, stop using the cup immediately and consider replacing it.

By following these tips, you can ensure that your eco-friendly reusable water bottles remains clean, hygienic, and in good condition for a long time.