Mentioning slipshod undergrad research or not in top graduate school applications? I am recently writing my statement of purpose (or research statement, if you prefer this) for my graduate school applications (in the field of EECS). I have two conference publications, paper_A in one mediocre conference (1st author) and paper_B  in one famous (but not yet top-tier) conference (2nd author).

I am completely happy with paper_A, despite its publishing venue being mediocre, simply because I did it completely myself and knew exactly why I was doing that. So I had a great time talking about that work in my statement.

On the contrary, paper_B, although accepted by a famous conference, really tortures and discourages me a lot while I am writing about it. Being the 2nd author, I now feel that there doesn't make much sense doing that work, and what we have claimed is weak and untenable. While elaborating on paper_B in the statement, I even gradually lost all the confidence about myself, which I have gained from writing about paper_A! 

My targeted schools are those top-tier schools. So I am afraid this slipshod piece of research may even backfire, since the critical faculty may find my work lousy.

So should I simply delete that paper from my statement and CV? But, its publishing venue is indeed a famous and widely acceptable one. Or should I present the complete me to the committee with all my works? But, will that piece of slipshod research backfire and hurt me?

P.S.: One side information that may help. paper_A is in the area that I wish to apply for, and paper_B is more like a side work, which I don't wish to continue in my graduate research.
As an undergraduate, you are not responsible for the scope and scale of research you are not directly leading. If a graduate student or PI is the one in charge of the work, you will not be "dragged through the mud" for having worked on it. In general, you are given the benefit of the doubt—you are asked to contribute to a project, and you do it. 

I don't think any committee is going to take a dim view of having published two conference papers while still an undergraduate. (And any committee that does probably represents a department you don't want to be at.)

If you are concerned about the impact, though, I would mention but not emphasize it. If you don't mention it at all, and somehow it turns up later on, it will raise more red flags than if you at least mention it in passing.