I've had Korean melon once in Jan 2014. I washed the seeds really well and dried them for 2 weeks and kept them. I proceeded to grow a few seeds and three germinated after like forever for me. I did not use heating mats or additional lighting, etc. So anyway, I put them in the back garden in the coop where I live and within a few weeks pests ate the tiny vines. I guess you can do the same as I did regarding saving the seeds.