Metal Ed, regarding your bottle stretch.
Is your penis wrapped around the underside of the bottle whereby your head is now facing up?
Also, when you say you grab just below the base of your penis, are you, with your other hand holding your glans so it stays in contact with the underside of the bottle?
Do you pull down, or rotate (spin) the bottle towards you, in effect causing your penis to follow the bottles’ motion, thereby stretching your penis in such a fashion?
Geez, a lot of questions, eh! Right now my brain is panscrambled, too much school information overload floating around!