Can we talk rooting hormone?

[Ray]

I recommend against using the powders with orchids, as they are 1) insoluble in water, and 2) the hormones are WAY too concentrated, and can damage roots on contact.

The most powerful root-stimulating auxin is the naturally-produced indole acetic acid (IAA). We have to settle for synthetic chemicals that are similar - indole butyric acid (IBA) and naphthalene acetic acid (NAA). Vitamin B1 is also a root-growth stimulant, but to a lesser degree.

Here is a comparison of the various products I've seen, it it suggests that K-L-N and the Hormex product - as they contain all three - are probably the best.