I suspect that the person making this request is trying to provide funds (Surprise!! You just got $50,000!!
) directly to the joint owner in the event of his demise, under the rules of joint tenancy with survivorship. There may be nothing nefarious about the request (but you should ask why).
If that is the reason for the applicant's request, it might be better -- and it would avoid all of the levy and attachment questions raised earlier in this string -- to use a POD structure for the account. And that wouldn't look at all suspicious, right?