The message
from Sacha contains these words:

Herbs seem the best bet in terms of being a concreted area and having to use
pots. Don't water them too much! If you grow Salvia turkestanica nobody's
going to worry about the dog pee. ;-) That's a joke, not a
recommendation! It's one of the most foul smelling but beautiful, plants
there is!
If there are any gaps in the paving, can you introduce some low growing
herbs which will smell nice when trodden on? Woodruff was used as a
strewing herb but I don't know if it had to be dried first, or not.

Come to think of it, fenugreek should mask just about any pong, and the
seeds can be used (ground) in curries, etc.

--
Rusty
Open the creaking gate to make a horrid.squeak, then lower the foobar.
http://www.users.zetnet.co.uk/hi-fi/