Is it a ‘‘rule’’ that in clubs or bars we double up ? dare i got to mg P75 ?? Also at my age 33 what kind of doses of TUTH or Ammo can i get away with ?? 
This is where you need to get out there and test comprehensively to see what dose range for different products/Putatives works for you in different situations - we can’t easily make this any kind of rule.
Yep. Agree.
And that is the rule. 
1st, no not a rule
2nd, I have found that certain mixes I can ‘double up’ but that’s because of buffering, one in particular I will wear 4 sprays regular strength TUTH in public and it’s fine. And I’m 29.
3rd, I think, theoretically you can wear an unlimited amount as long as you can adequately buffer it.