1: Kissin' Kate Barlow (Katherine Barlow)'s famous spiced peaches, fermented over 100 years, sealed tight in glass jars. Sam had several jars stored in his handmade boat, Mary Lou. When Sam was killed by Charles "Trout" Walker, eventually the boat and Sam's body sank to the bottom of the lake, where the boat had overturned. 20 Years later, the lake had dried up, and Kissin' Kate Barlow found the remains of the boat after she'd buried her chest. She was lying against it when she was confronted by Trout. A Yellow Spotted Lizard had used Mary Lou as a shelter, and Kissin' Kate allowed it to bite and kill her.
When Zero (Hector Zeroni) escaped from Green Lake, he found the Mary Lou, and used it as a shelter, finding the jars of fermented peaches. It was still edible, and tasted good. It was sloshy and mushy, so he nicknamed it `Sploosh'.
When Stanley found him 3 days afterwards, Zero was still alive thanks to the shelter and the Sploosh. Zero gave Stanley some, and Stanley said it was actually good.
Unfortunately, too much Sploosh caused Zero to get sick. Sam's onion field on God's Thumb cured him of that.
2: A powerful deodorizer / spray made with peaches and onions.
Later in the film, all of the former D-Tent boys watch Clyde ''Sweet Feet'' Livingston's commercial for Sploosh foot spray. Stanley Yelnats III - by a stroke of luck - found that peaches and onions were a cure for odor. They marketed it, and were able to afford a lawyer to get Stanley IV out of the camp. After opening Stanley Yelnats I's chest, the treasure allowed the Yelnats to afford a huge house - Hector used his share to find his mom - as well as afford a new house next to the Yelnats'. They also got Clyde "Sweet Feet" Livingston himself to view the commercial with them.
Sploosh was marked under the brand name KB Industries, in honor of not only the tube of lipstick that helped bring about the downfall of Camp Green Lake and The Warden (Louise Walker), but for Kate Barlow herself - her stolen treasures helped bring everything together. And at the end everybody starts laughing and agrees with Clyde ''Sweet Feet'' Livingston's commercial.