really? it seems to work for everyone else who uses it for just this task. perhaps you are using it the wrong way?
I really wouldn't recommend you boil bogwood; it can make it fall apart or rot. Pour hot water over it and leave it to soak. Change the water every day and the tannins should soon go, though it does depend on the wood; some pieces leach a lot more than others.
well said there.
all boiling does, is increase the speed that the wood will degrades.
unless you boil it till the wood falls apart. all boiling will do is remove tannins from the damage wood. and give access to Undamaged wood. which will




start giving up its tannins.
water change and, if you like adding a carbon filter (I, personally, wouldn't add it to your current filter) coupled with time, is the best way to cope with tannins.
its also worth considering that tannins are, usually, said good for fish. well, there is defiantly nothing bad in there anyway.
I find its gone, to the human eye, after 3-6 months anyway. via water changes.
even without a carbon filter. which is the best way to get rid of tannins. quickly
so the problem is down to aesthetics. if you dont like brown water, and you dont have fish that eat/rasp it. get plastic wood. problem solved!