I had an L4-L5 injury almost a year ago, and I use an inversion table from time to time when my back is a certain type of flared up. Sometimes it’s spasms and I can’t hang. But other times its different (can’t quite explain it) and hanging is very effective.
Not sure I would ever throw it in a gym without some fair warnings to all lifters who use the gym. It’s not to be used before, or during, a workout. Use it on off-days, or after lifting/cardio is done.
If I’m in a gym without a table, or away from home, I just attach bands to a rack and hang, like monsoon said. I’m 260ish, so I need a bunch of bands, but it works similarly although far less comfortably. Look up a YouTube of Donnie Thompson showing you how a 350lber does it.