I think you can trust this source:
from page 3:
“Severing of the suspensory ligament enables the penis to extend closer to its erect length while flaccid. But this is not a guaranteed result. Some men will not gain any length or will experience a shortening due to fibrosis (shrinkage and toughening of tissues). Many doctors who perform penile enlargement and lengthening suggest that their patients buy a “Penile Tissue Expander” (Ken Jons, undated). The Expander “promotes the healing of the penis in the most outward position.” The device consists of a weight system taped onto the penis to be worn six to eight hours daily. The patients are advised to start using the Expander five days post-op and continue indefinitely. One man wrote Ken Jons and asked why his penis seems more flexible at the base. Other questions involving sexual activities were also printed in the “Penile Tissue Expander” article. This implies that there are pertinent sexological issues that need to be investigated thoroughly. “
It’s a wrong deduction that if Penimaster wasn’t useful for you, then penile surgery would be a waste of money?