We have been growing Luffa squash for a couple years in the garden. Luffa squash is a tropical plant native to Southeast Asia, so here in the North, the seeds need to be started indoors. Starting indoors will give it the longer growing season it needs to develop its fruit.
After the squash has dried for about a month, roll the squash on a table top to loosen up the skin. I split it open and peeled back the skin to reveal the sponge inside! Clean out the seeds and gunk (jelly-like substance). I use an old toothbrush.