Andrew wrote:

Luckily Google found "Bostic Cementone brick sealer" and it was out
of stock online and only one 5 litre can left in the south of england
in Leatherhead, so I drove there and grabbed it. I think VOC2010
or whatever has consigned it to history.

They've got plenty in Wickes an Travis Perkins, rather than ToolSatan
(obviously they're essentially the same mob)