I recently got my girlfriend into filling her panties with whatever items I say, she loves it. We have tried honey, oatmeal, jelly, applesauce, pasta. What else can we try? We are kind of out of ideas already. She absolutely does not like beans and prefers warmer stuff.
I personally love chocolate syrup the most. It's the end of the panties, esp. if they are light colored, but the silky feeling (also, wear nylon/satin panties for extra niceness) is really wonderful and sensual. Avoid strawberry syrup, though. She will understand why and thank you. I did it once and after looking down, it was so...incredibly unsexy lol
Mud is also delightful! It has a different texture but it's got that nice slippery feeling if you don't make the mud too thick. If it's made from the right kind of dirt, the texture adds a really extra bit of pleasure when it rubs against my labia, so I recommend trying it.
I've done lotions and shampoos because they are slippery but they fell flat for me because they felt too clean.
Let's see...what else? Pudding is kinda meh because it jiggles and doesn't flow well. Too lumpy. Look for things that are more vicious and silky in feeling.
I am partial to molasses. Like Justine said with chocolate sauce, your partner will definitely feel like she got dirty, and the panties will be trashed. I like to pour it over her chest and watch it flow slowly down over her stomach and into the panties that I am holding open with one finger.
I also prefer the flavor to chocolate. Part of our deal is, if she gets dirty down there, I'll make it up to her by licking her clean. Win-win.