What do you mean by “work”? From the rest of your question, you seem to think that attraction and feelings means that the “friends with benefits” relationship isn’t doing that. What is it you’re trying to avoid?
If you think this is a rhetorical question, it isn’t. I don’t have the answer for you. If developing feelings for somebody is truly something you want to avoid, then yeah, friends with benefits won’t ever work for you. Nothing will. Because feelings and attraction are a natural part of human existence.
What I want to tell you is that it’s way better to just let feelings develop and then if it gets messy then it gets messy. I want to tell you that having sex just isn’t really all that worthwhile without those feelings or that potential for messiness. I want to tell you that you can’t and shouldn’t even bother trying to control where those feelings take you.
But I can’t tell you those things because the wording of your question indicates that you’re not really interested in truth. You want to be lied to, to be sold a vision of perfect sex that you can hold in your hand and pose like a Barbie doll. You want to be told that a friend can remain a “friend”. That there’s a way to have sex without having to deal with this friend’s emotional needs or finding out that you have emotional needs that need to be met too.
So you’ll just have to find these things out, by screwing up your friendships by having sex and then refusing to deal with the resultant feelings and emotions. Or not having sex and still refusing to deal with the resultant feelings and emotions.
I can’t give you the answer you’re looking for. At some point you’re just going to have to deal with these inconvenient things.