Applications of 3-collisions
There are more recent papers that cite Joux and Lucks.  Example: "Preimage Attacks against PKC98-Hash and HAS-V", Sasaki et al., uses the Joux-Lucks algorithm to attack two hash functions.

Have you looked at newer papers that cite Joux and Lucks?  Have you done a literature search, to find newer papers that cite their Asiacrypt 2009 paper?  Google Scholar, Citeseer, and Microsoft Academic Search can help you here.  That'd be a good start.  If someone uses the Joux-Lucks algorithm in their work, they'll probably cite the Joux and Lucks paper.