Fred from Bryn Mawr, Pa writes
have been using Physan 20 and Bayer Natria with variable results
Orchids can be very delicate and we are not very knowledgeable about them so we are hesitant to recommend any products for use on them. Instead we recommend you speak with someone from your local extension office who may be able to put you in touch with an orchid expert. We apologize we could not be of more help in this situation.
Answer last updated on: 06/02/2013