Well I have not had a chance to do much with it. It is still soaking in vinegar. I looked for a baby bottle brush, but my wife had just recently thrown then all out. I was going to do the chopstick with paper towel method, but the curve of the spout will make that impossible.
I am fairly confident that with a regular sponge I will be able to clean it out well. I do not think anything got up that far into the spout thankfully.
I was just in the tea shop today looking at new pots just in case though
and to buy some delicious looking white tea.