I recently saw a provider who gave some outstanding DT, all the way to the root. I complimented her on her skills. She said when she was new, she would use Chloraseptic spray on the back of her throat before an appointment, which completely numbed her throat. Eventually, she got so used to the feeling that she stopped using the Chloraseptic but had lost her gag reflex. Just curious if other providers have tried this...
using olive oil lol.
Linda Lovelace of DT fame was said to use good old vaseline to coat her pipe before saying hello to Mr. Holmes.
Then again, so does stomach slime.
I like using Listerine strips, it gives that stay fresh after sex tingle!!,, LOL
I know I am in the minority, but it does nothing for me. All the sensitivity is on the top.
Of course no one would ever gag on my 3" anyway if they did DT me 
that when the tip is down her tight little throat and her tongue is caressing your balls, it feels AMAZING!