I have used silica gel
It really depends on the size of the tent / environment and using enough product to make it work.
I have also tried Rock salt, rice bags…spreading the material out for more surface exposure. I placed trays of salt / rice, under my plant stands. Was messy…but worked. I also had an enormous grow area 2500 sq ft plus. The a/c, dehumidifier electric cost was too high and I got so tired of emptying the water buckets
Inside my 8x4 tent, the exhaust fan takes care of it all (soil grow, not hydro - in hydro, you can seal off the reservoir / buckets so the only the plants add moisture to the area, not the medium)
I get better results using my exhaust fans, like Rye says, and I am careful on my watering that I water different plants on different days so I reduce the respiration. I also watch temps…lower temps, lower Rh.