On 2018-02-05, stuart noble wrote:
IME sealants produce a "wet" look, which may not be what you want.
Usual guff on the website about an "impregnator", and then an
invisible, yet breathable, film. Eh? Also, silicone tends to
collect grime. I've used Thomsons Water Seal on outside brickwork
and, from memory, that doesn't form a film

Interesting - thanks.
--
Nick