Well, back in the olden days when we rode the back step we had them affixed to the hand rail as an extra means of hanging on. When we got to a scene we just unhooked them and put them in our pockets for possible use on the fireground.
You can tie a hose strap to a larger diameter attack line "ie. 2.5". One end around the hose and the other over your shoulder or around your waist. It will help you control the hose, take some of the weight off, and negative pressure off. I have used a hose strap in training to tie hose off a ladder. A hose strap is basically webbing. I have used webbing in training to tie a pt. into a stokes basket. Use your imagination