Has anyone has success using sand timers with their 17/18 month old?

I'm wondering if my daughter is still too young to understand the concept of a sand timer.

She OBSESSES with playing in the water when we wash hands or brush teeth. She loses her mind when I turn off the water.

I bought a 2 minute sand timer to try out hoping over time she'll understand she can play in the water all she wants until the sand runs out then it's time to turn off the water and move with our day.

Any thoughts?