I'm just interested in what people's favourite substances are when it comes to clothes filling in particular. I've used quite a variety of things myself, but now seem to go back to the same things, beans, custard, gunge etc.
I've always found warm porridge to be my favourite!
Also grabbing the thickest gooiest squishiest gateaux from the frozen aisle, defrosting it inside the crotch of a swimsuit, and gently pulling the swimsuit on while trying to keep the cake intact...
I'd love to try custard down my pants, but it is not available here in the states. I've been told bavarian cream pie filling is almost the same. I've enjoyed grape jelly, and thick syrup down my pants
It's really smooth, the coverage is just like paint and the sheer mass gives an amazingly 'weighty' feel. (It also makes fantastic squelching noises as you massage it about in your tights and panties! )
It just rinses away without leaving a mark (but you need to try to recover as much as possible into your bucket anyway, both because then you can 'go again' but also because you don't want to risk blocking your drain! (Lots of flowing water required.)
My favorites are the thicker items that I can hold inside for a while. Oatmeal/porridge, mashed potatoes, and beans. I have been wanting to try thick slime for a while.
I love porridge. I put 3kg bags in a bucket, add hot water. Wait till they soak up the water, then blend with a stick blender. Not till totally smooth but so there's still some bigger bits. Feels so good inside a swimsuit.