Deflasking is a delicate process that demands a fair bit of TLC and careful attention. Using a gentle fungicide is a must for this job, and any mistakes can potentially compromise the whole batch.
Using a very diluted solution of physan 20 when de-flasking will ensure the future success of your lil' wee ones.
USE : low dilutions of 1 teaspoon of Physan 20 concentrate per 3.8 Litres of water.
(may vary on different orchids - if a weaker solution is needed for especially fragile specimens, then only half a teaspoon per 3.8 Litres of water is needed)
Spray seedlings all round as you repot them into their new medium.