I think that I may be able to help on this one.
Whilst on a recent trip to the yacutan pennisula I stumbled upon some crystals in a restaurant ashtray. When I asked the waiter what thay were for he said that when a cigarette contacts the crystals a lovely pungent aroma is produced. I found his claims to be totally accurate and the restaurant became engulfed in a lovely mist of sweet smelling clouds. He went on to explain that during the reign of the mayan civilisation, high priests used the crystals to disguise the smells generated by the peace pipes. During the ninth century the main element of these crystals was human blood, however this has now been replaced by ox blood.
This product is now readily available in most branches of Robert Dyas and is known as 'fAgaway'.
hope this is of use to you