This "tradition" is also done at other campuses - but I've never heard of it for dropping/lavaliering - usually this "high honor" is reserved for either pinning or engagements.
Not a local tradition at all...and, some of the variations I've heard being considered - he's lucky he at least got to wear something, even if it was saran wrap....
Speaking of saran wrap - we had a toga party once way back when, and one brother decided that would be his toga material. He was also one of the stunningly brilliant brothers who couldn't figure out why our chapter got closed in 1989...