How to use Boeshield T-9 in general?
For a heavy film; Put on T-9 and leave it on. T-9 will dry into a thick protective layer.
For a thin film; Put on and leave on for at least 2 hours so it can fully penetrate the metal. Afterwards wipe off the excess.
T-9 dries to a waxy waterproof finish without leaving a sticky film to attract dirt.

How to use Boeshield T-9 on your bikechain?
Cleaning the chain before you start isn’t necessary, but always better.
T-9 will really penetrate into the smallest parts of your chain so all existing dirt will flush out.
This will be visible the first 2 or 3 times you start using T-9.

Put T-9 on your chain, make sure this is enough to fully penetrate all parts of the chain.
Leave on for at least 2 hours (preferably overnight) to guarantee full penetration.
Afterwards wipe off with a cloth.

On the outside of your chain you will have a non-sticky protective film that doesn’t wash off or pick up dirt.
And on the inside of your chain a waterproof lubrication that lasts for miles.

Youtube.com:

Waterproof with Boeshield T-9

Rust-proofing your bike frame

Rust-proofing your bike frame (no sound)