Manual work will always be more powerful and effective because you're exerting more energy from the inside. Also it's a full-body workout. I use my legs, arms, ass, and abs for all my workouts.
But tools like [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]SG[/words] is appropriate for extended healing, since we can't walk around bent over with one hand in our pants LOL!
But you can also do manual work within PE devices too, like [words=https://officialhydromaxpump.com/?uid=6&oid=2&affid=98]BM[/words] Hardcore Stretches for instance. But solely letting devices do the work is kind of like just doing weightlifting without getting your core muscles corrected and strengthened first.
I feel that before going into PE tools one should condition the penosaur with manual work.