ACDC Spray Dosage

My son suffers from Tourette's Syndrome. He is 29 years old and has been dealing with it for almost 20 years. He tried some ACDC spray tonight based on the advice of a lady who works with cancer patients and is well-versed in medical marijuana usage.

That being said, he tried the spray for the first time tonight and there really weren't any "instructions" on how much to use or the frequency of use. He tried one spray and nothing really happened. After a few minutes, he tried again with a couple more squirts and his tics stopped but only for about 15 minutes or so. That is HUGE progress but we really have no idea how much he should use. Our friend I mentioned above said he should try the ACDC tincture but we couldn't find it near us so he tried the spray.

Does anyone have any kind of advice or guideline on how to determine dosage and frequency or is it just hit and miss? If we could find the right combination and such, it would be life-changing for him. Just for the record, he won't vape or smoke (work reasons) but tinctures and sprays are OK.

Thank you!