Chemical laws aren't personal opinions; if a procedure reflects or not some chemical law, that's no an opinion: if you comply with it you get good result, otherwise you don't.
Anyway, thank you all for your suggestions.
I'd have to agree that "Chemical laws aren't personal opinions", but Cardiwen is still correct as there is no evidence out there apart from each DIYer's own trial and error and their personal opinion on their results.
It's funny how some people are so sure of one result but others are just as sure of the opposite.
My own opinion is that no 9mg juice would give me a TH i'd be happy with and that I personally would have to up the nic (and maybe PG content) to get a good TH. As for flavour, I've had some bad ones but I really doubt any amount of heat, vibration, cap off or shaking would have made them better. I'd try a different flavour, or try adding something else to improve the flavour you have.
I give all my 'attempts' a good week to see if they improve but I can only see much of the above advice as superstition
