11 Ways to Completely Ruin Your plastic tongue cleaner
https://franciscomqnx679.skyrock.com/3324653874-10-Principles-of-Psychology-You-Can-Use-to-Improve-Your-tongue.html
A simple and effective tool. Do not push too hard, or you will cause the tongue to bleed. That sounds like common sense, but it is much easier to cut yourself with this than you might imagine.