You can immerse them in water for that period of time but you shouldn't use that same water for other plants as you could (and it has been proven) spread viruses.

I pre-soak bark before I use it for a minimum of 2 days with a little dish detergent and agitate the bark a few times a day. Use only whatever is floating. Use what has sunk as mulch in your gardens. A week later after potting, mist the top of pots daily in addition to your regular watering.

I immerse or "dunk" most of my orchids. I buy old tupperware bowls at Goodwill or second hand stores to use. You should not use the same water for each plant as, stated above, you could potentially spread a virus. I normally soak my bark before I use it. I also add some cinnamon to the bark when potting. I do not dunk them for more than 5 minutes. But the length of time would depend on how quickly the bark can absorb water. I find this method a little time consuming but it reduces the occurence of crown rot or water sitting in the crown of the plants, especially Phals.