I think it's being seen from our adult eyes first I would imagine they are not intended for kids at all and it is inappropriate to have them where they can get them but having said that I doubt they will harm or sexualise either little boys or girls they will just see it as funny in fact hilarious to bite a body part, especially a willy.
They wouldn't inspire me to buy them nor the chocolate body parts you get nor the calendar my 13 y old granddaughter passed on to me as she didn't want it, her friend had brought it back from her holiday and was a calendar of 'willies,' I put it in the bin not because I was shocked but I thought it was a bit poorly made with very small spaces to write in and not worth keeping
I personally think there are much bigger things being sold to get worried about, the slogans on some little babies or toddlers t shirts to start with Baby and children's pageants which are hugely sexualising, music videos and words that even little kids use and see
Biting heads off naked (shock horror) jelly babies or sugar mice was one of my delights as a child but it's ok I didn't turn into a mass murderer