It is easy, for
SG I do half hr rotated to each side then an hr regularly stretched, only thing is when bundled you need to take bars out then replace them quickly for the regular stretch. Manually they're good, I'm more of a girth guy I've probably gained somewhere around half an inch to 3/4 in length but honestly i'm not as consistent as I should be in stretching. Yeah also a good way I've been trying bundled stretches was someone here I really don't remember who or where it was, posted a video on using drumsticks to twist the penis around and it's pretty intense. I'll see if I can findthe link for you.