Summarize:

Close your left thumb in your left hand and make a fist. Position your thumb under your fingers. Squeeze tightly without causing yourself too much pain. Moisten the tip of your finger, dip it into some salt, and touch the salt to your tongue. Salt activates the taste buds on the front of your tongue and sets off a chain reaction that temporarily suppresses your gag reflex. Another way to do this is to put a teaspoon (0.99 metric tsp) of salt in a glass of water and rinse your mouth with that. Don't forget to spit! When an object touches the soft palate, it can trigger the gag reflex. Use an over-the-counter (OTC) throat-numbing spray like Chloraseptic to desensitize your soft palate. Alternatively, you could gently apply a topical OTC analgesic with benzocaine using a cotton swab. The effects should last for about an hour, and your palate will be less reactive.  Throat-numbing sprays rarely cause side effects. However, you should stop using it if you experience vomiting, nausea, dizziness, drowsiness, and/or stomach cramps.  Use the benzocaine remedy with caution. The cotton swab could trigger a gag or choking reflex. Other possible side effects include fatigue, weakness, skin irritation around the ears, blue skin around the lips and fingertips, and shortness of breath.  You should avoid the benzocaine remedy entirely if you’re allergic to benzocaine. Ask your doctor or pharmacist about interactions with other OTC medications, vitamins/supplements, or herbal remedies you might be taking.
Squeeze your thumb. Put a little table salt on your tongue. Numb your soft palate.