Using a poison known by name only elicits suspicion. The truly perfect assassination is one that remains undetected. I would not brag of those slain by my concoctions, for fear of breaking the tender illusion of "natural" death.
I have penned down one of my favourite mixtures, in hope the reader will seek out more on there own. The preparation is unorthodox, yet it has served me well.
Prepare a fire, burned down to coals. Atop that, place a large cauldron. This will be your crucible.
Add to this a drop of your own blood. It will sizzle when the pot is tempered. You only need the residue of blood for flavour and scent.
Scrape the salt from a mangrove leaf, and powder it with the spores from a yellow-knight mushroom. You can find these growing in almost any field if you lie down with your face to the soil.
While the crucible is still hot, pour a decanter of treacle tea in, letting the steam escape. In a short time it will reduce, and to that sticky mess, you will add the aforementioned powder.
Once all the ingredients are combined, it's ready to use. On the skin, it breaks down strength in a matter of hours. For a faster reaction, ingestion or wounding is best.
I have yet to calculate an antidote to this recipe, so I advise using the utmost caution when handling.