Hi Carol! Its a 2 liter size bottle with the bottom 3 or 4 inches cut off turned around and pushed back in to the bottle. Acts as a platform which is easily removable for maintenance, visual checks. I keep the lid on as my object is to achieve very high humidity for the victim. Its suspended because up there is shady and warm and ideal. First step i soak plant/s completely leaves and all for 24 hours in a bucket of water with a slightly stronger dose of superthrive and a weak dose of tomorite because it has seaweed extract in it, a cup of sugar and a pint of full milk for the enzymes and other chems to act as a natural fungicide.
With the bottles ready, paper towel in folded into a square shape, dampened and put on turned up severed bottom. Orchid is appropiately positioned and pushed into the bottle using your palm. The next day and for 3 days consecutively the screw lid is removed and sprayed in hole with a mix of hormone and water. I use Baby bio liquid roota. A whole 100ml is mixed with water to fill a 1litre spray bootle.The consistency is slightly thickened. Everyday for 2 weeks to a month you just take plant out move foliage about and put back. Must be kept warm so the condensation forms in bottle. Success and time length differs with severity of victim but is reliable for me. For 6 months after the root success its fed a 30 10 10 ferrtilizer and cultured as prefered or suitable. Oncids often fall victim for me along with some other kinds on occasion and my method often comes in useful. But what works for me may not for others.