I've seen everything now.
My search history doesn't bear looking at. I have googled how to poison, stab and murder (research for novels - honest!) and checked that you can get slow match (Digging up the Past had slow match which you can get on Amazon but the version in the book burns quicker). I have found arsenic on eBay in its mineral form. I assume that anything to do with sex is out there, but I haven't really looked that closely.
Now I have found that you can buy Holy Water on eBay. It does make it easier for a would-be vampire killer, but really! Look here if you want! There is a picture of Our Lady of Lourdes on the side of the bottle. It just seems odd to me, selling Holy. I know priests have to live and that the places where people meet to worship need upkeep, but it makes me feel uneasy in ways I can't work out.
I wonder what would happen if a would-be vampire hunter bought some Holy water from the internet and it was fake?