Pharmacies in TN are getting so bad due to the nefarious acts of others that as of late, they are now locking down Pseudoephedrine to the max (i.e. the stuff in Sudafed). If *they* don't think you need it, cold or not, they won't sell it to you. So this basically allows pharm techs the ability to discriminate based on request.
Never mind asking about PG/VG, because they need your name, address, phone number and date of birth accompanied by a valid state ID. I was in there a few months back asking for syringes (i.e. w/o needles) and they had me fill out what looked like a questionnaire and sign for them like a prescription.
I get it, they don't want people buying pills and needles and doing god knows what with them, but I don't see a ton of druggies walking in asking for their fix of PG/VG and if they can get it premixed.
For those vary reasons, I try my best not to go to any pharmacy as I don't feel like being treated like a criminal. I refuse pain pills at the doc when I do go, so that lessens my need to visit them in the first place. I've had better experiences with Military Doctors and Techs than I do civilian.
I didn't know you could still buy pseudoephedrine, I certainly miss sudafed when my allergies act up.
Maybe you can use PG/VG in a way we don't understand as we aren't chemist. If it's used in glycerin soap making then it can be used in nitroglycerin making.
As far as pharmacist discretion goes it's even more laughable than you think. They can deny a valid pain medication prescription even after verifying it with the prescribing doctor.