Tongue scraping is for people who can't brush their tongue without gagging, and is quite successful. However, when I was tongue scraping I would gag far more
violently than when I brush my tongue. I'd rather gag 5 or 6 times, than once horrifically. Even tongue brushing often gives me stars in my eyes and a light instant headache. I do recommend tongue brushing at least, and if you can handle it, tongue scraping. It doesn't hurt... its usually just a plastic loop that you place on the back of your tongue and then pull forward once along your tongue. Its main benefit is you get to see, on the surface of the loop, all the crap it has pulled off your tongue and is quite verifiable in that respect.
The best tongue scraper I ever used -
http://www.edupics.com/tongue-cleaner-t7511.jpg
Helpful short article with picture of scraper in use -
How to clean your tongue in 5 minutes | Just In Five Minutes
Most bacteria sits on the back of the tongue, and is the main cause of bad breath. In terms of
vaping, I notice my skanky breath disappeared after I quit the nails - now for the last two months. No waking up thinking the cat has cr***ed in my mouth at night. I remember the first week waking up and thinking Ooo, fresh breath.
So ultimately I'd agree with others that the OP's bad breath is most likely a combination of bacteria on the tongue from insufficient tongue brushing/scraping, mixed with dry mouth. Smoking all day my mouthwash would last about 2 hours before my mouth tasted like I had dumpster dived with my mouth open. Now with vaping... all day freshness. It has restored my confidence talking to those who don't appreciate my personal circle (ie you don't need to stand 2 feet from my face to talk to me... gtf away from me

).