The
lengthmaster by itself or with resistance bands is probably the best length workout you can ever have besides hanging but there's something about stretching with my hands that makes it feel so effective and intuitive. When I stretch or jelq with my hands I get better "feedback" if that makes sense. It's more sensitive. But the downside is that it isn't very good on the body.
I know I've said this before and it's a huge buzzkill but I am fairly confident that manual pe work is ergonomically not good at all on the back, neck, and shoulders. I try to limit my manual work and to stretch my muscles and hang upside down with teeter boots to stretch out my spine and decompress the discs. Deep tissue massages are also incredibly benifical.