I wouldn’t use a lot or often because if your environment stays the same it won’t be much help anyway, it will just melt fast and go back to the same temps.
Its just a quick solution if there are time constraints like waiting on hydroguard because you can’t make the room any cooler.
My temps stay between 72 - 73.9 I use hydroguard because its not much else I can do other than moving my unit to the basement where its cooler.
My plants function well as long as I use the hydroguard once a week.
P.s no known reports to suggest it effects the roots, although many of us have tried it.