Another generous helping of Fun With Brickwork. My friend was able to lend me an SDS. It's still slow work but it's incomparably faster than doing it by hand and vastly cleaner than using an angle grinder.
In the first half hour or so of getting to grips with what it can do I managed to chisel out the mortar around one entire brick and nearly dropped a 10lb lump on my foot, as it fell out of the chimney stack unexpectedly. Tomorrow when it's daylight I can hammer around at least the top bricks. I'm hoping I can get this entire stack out within a day or two, before my friend needs his tool back. If needs be I'll go ahead and buy the one I had transferred to my local hardware store, but I'm really hoping I can finish before then. On another positive note, the one I borrowed is the smallest of the three models I was looking at, which means I can potentially get away with $300 rather than $500, if I do end up buying one. I may yet go for a bigger one for the extra speed, but with any luck I won't need it at all.