Okay mate. Sounds cool and the sea clamps (small size underneath the head) worked well for me but I went with the condom rim. Please do wrap underneath the head with a thin piece of cloth, only needs to be small and nothing fancy just to take the edge off the gripping clamps because it
could trap a nerve in the area. I think 10 minutes is enough but try 15-20 minutes in the near future as you progress.
The hard part when doing Boa's is keeping aroused, because I don't masturbate the shaft of my penis ... just pull the foreskin backwards and forwards over my glans (If I was a women I would be a clit orgasmic whore) but with this I cant as the skin is clamped down, so I have to REALLY concentrate and is why I love doing these inside the
Bathmate ... the vacuum is keeping me erect. Remember whatever route you choose to concentrate, remain focused and KEGEL ... that is often overlooked but keeps new blood coming in to engorge and also jelq to get blood in the region and squeeze underneath with short holds .. great expansion.
I think you would be best with the
X-40 but you may at first get sore testicles as members here have reported that with the
X-40 when they started. I myself had this problem but it sorted out after a few weeks and at the 10 minute stage I just let them go inside the
Bathmate, which has done WONDERS for the hang and health to the area, including getting rid of a dull ache I often got in my scrotum ... now gone.