Fairy Cave is not a legit venue for dry tooling. There is a chalk quarry near Salisbury which is used for that sort of thing but I don't know of anywhere else.
There may be no known venues, but if there's one chalk quarry there'll be others. SPend a wet SUnday with an OS map driviong round and you might be rewarded.
thanks guys, was alot wetter than i expected. the gorge had become a fast moving rocky/gravelly steam way, driving up it wont be forgetten any time soon.