JFZ, I wasn't BS but I know of a couple of instances. At Scampton they had and HTP off-load pit. A fireman accidently fell in to it and as quickly came out again as it blew him out - he was shaken but not stirred. I believe they also had drench showers available.
On another occasion, a Vulcan with a hot missile landed at Waddo and used the emergency HTP offload area - no pit, just the grass on the side of the taxiway. I saw the correspondence between OC Ops with ours asking for a supply of grass seed.