Weed removal from chimney

I am hoping that someone could provide the name of a suitable weed killer for a large weed (which more resembles a branch from a tree!) to be removed from the chimney of an old recently aquired property.

A number people have advised not to use force removing it as doing so could erode the internal brickwork which could lead to leaking etc. The idea is to trim it back to the stone and use some form of weed filler to kill it but considering it is more wood than weed a very powerful weed killer is needed. Any assistnace would be greatly appreciated.

Thanks.

Woodies or any hardware will sell you a product. Can't remember the names of any offhand. DON'T cut off the leaves or trim it back too far as most of these products have to be absorbed through the foliage!

Thanks Liteweight for the advice. Will try Woodies or similar to get something similar.
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