When Janet Lamborn spoke to our orchid society, I did feel like I was listening to an infomercial but she had a lot of good information too. I decided not to worry about it but to be aware and do what I can to keep viruses out of the GH and control any I might already have.
There is always Physan for sale at our orchid society meetings (along with other 'necessities'). I think I'll get a bottle next meeting.