I only use straps when I’m doing exercise and my grip starts giving out. Using straps allows me to take exercise to complete exhaustion. I use to train forearms. I discovered that just hanging from pull up bar with towels wrapped around it for as long as I could giving myself little break than repeating caused them to grow the best. When I want to work my forearms I now will wrap towel around pull up bar or deadlift bar when doing those exercises.