Don't soak the orchids all in the same water. Not even two in the same water. This is how infections and other nasties spread. Use the Bayer 3in1. It works very well. This way it even gets into the nooks and crannies of the leaves where stuff can also hide.
I sometimes submerge the entire plant in a 5 gallon bucket of water with Bayer or malathione mixed in. I soak each plant for about a minute. I tried drenching them but found it didn't get into the holes and interstices as well. When I lived down in San Diego I had ants take up residence in my cyms occasionally and just spraying didn't get them all. I started soaking and never had any aftere that.
Don't soak the orchids all in the same water. Not even two in the same water. This is how infections and other nasties spread. Use the Bayer 3in1. It works very well. This way it even gets into the nooks and crannies of the leaves where stuff can also hide.
i used different buckets for each. i had like 10 5g buckets on the grass! and dumped them out about 5 times each!