So my question is is it totally safe? And any advice on easy to put hangers?
It is safe if as long as you pay attention.
I gained 1.25” in four months/140 hours hanging no more than six pounds, back in 1996. The AFB hanger I introduced over ten years ago remains the simplest, cheapest, and most universal, inconspicuous, and adjustable design for a hanger.
That said, I no longer recommend hanging, and not just because it’s boring. For a while now, I’ve been interested in what routine leaves your dick (BPFSL) bigger immediately afterward. I found that prolonged stretches—and this, to my surprise, included hanging any amount of weight—did the exact opposite. My thinking may be simplistic, but doesn’t it make sense to do a penis enlargement exercise whose immediate affect is to make your penis larger, not smaller?