[header] How to clean your tongue without gagging [title] Try a desensitization process on your gag reflex. [step] While you might assume that your gag reflex is set in stone, it may in fact be possible for you to retrain and reduce it. Basically, you want to slowly and steadily take yourself to your gagging limit, which will over time creep further back on your tongue. 
[substeps] Stick your tongue out as far as possible, and press it down against the bottom of your mouth. Start to gently work your brush or scraper back from the tip of your tongue.