I don't. I am not familiar with the product. I figured I would answer you because other wise it will sit here forever with no answer, and I didn't want you to think that no one has read your post.
Susan

Not sure if you want to make the gel soap from scratch, or if you are just wanting to make a gel soap that smells like the Neutrogena Rainbath...

If it is just the fragrance you are looking for, in a gel-based soap, here is one way to do it.

The Chemistry Store has Pure Organic Vegetable Castile Liquid Soap gel base that you could add the Neutrogena fragrance to... (scroll way down to find Neutrogena on that page).

If you enjoy making stuff, be sure to browse around at the Chemistry Store link... they've got lots of fun stuff! I've bought from them several times and have always been pleased with what I got.

Thanks for this link, Red Confetti. I am unfamiliar with The Chemistry Store, but I am going to browse around. I have been looking for an organic liquid soap base.
Susan

Hey!!! I'm Kylie I usually hang out on the junk side. I'ts a little slow and I'm neeeew soo.. I thought I would see some of the rest of the garden web world.