In reply to Ciro:
>
> I seem to remember watching a video a while back of some sponsored climbers doing exactly this in scandinavia, so I assumed there were certain rock types where it was safe.
>
Not just sponsored climbers in Finland. I think there are a reasonable number of people doing it. The rock is granite and probably more resistant than most rock types but I always thought it was a really silly idea.
I've seen people drying holds on Normipaiva with a blow torch. It seemed a really good way to ruin a really classic problem and at that time one of the hardest in Finland.
For those who don't know Normipaiva