I used Formula 420 until a cute girl in a shop at the Haight told me it was basically alcohol and salt. I’ve been using the latter for years now and never looked back. I use the 90% rubbing alcohol from Target & the cheapest salt you can find (you only need it for its abrasive quality). I was told years ago the 90% worked better but I’ve been recently informed the 70% may actually work better based on its higher water percentage.
Maybe some more sciencey BBers want to weigh in on this?
The above only applies to cleaning glassware that’s been used for smoking herbal flowers. When cleaning a “dab rig” (a pipe used to vaporize concentrated herbal materials), neither Formula 420 nor alcohol/salt are very effective against heavy oil build-up inside the glassware. For that situation, I recommend acetone (with proper gloves and ventilation). It’s strong but it only takes a small amount to clean oily glassware right up. Acetone apparently dries without any residue but I always to a light follow-up rinse with alcohol and then water. Result: sparkly clean!
