Do Phallic shaped Ukirans have any traditional background?

[milandro]

I sometimes see for sale keris ukirans shaped more or less obviously like a phallus. I always see them go very quickly which must mean that they are appreciated but is this something that has any base in a tradition or is just a gimmick ? I can't show any because what I can find are all for sale and some may be offended by the graphic nature of the images