Only roots and spices. Ginger root and cinnamon powder and oil. Interesting sensation play.
For ginger root, search "figging". It's often used anally, though I've had it used vaginally too with no ill effects - ymmv.
For something less penetrative, cinnamon powder poured on a vulva/clit produces a burning sensation - we avoided the vagina, wouldn't recommend it because I haven't tried it, but wetness helps.
Cinnamon oil (food grade) needs no wetness and will produce heat and burning on nipples, clits and other sensitive bits - also wouldn't recommend it internally except via the mouth, simply because I haven't tried it.
There's always hot peppers, although I'm more partial to things that smell better.
my master had pleasured me doggystyle w/ my knees digging into uncooked rice. i was penetrated w/ zuchinni. nice texture. nothing too crazy but still a memorable expierience. of course i wanted to beg for something attached to him but i was afraid he would upgrade to squash or eggplant or something of that size for speaking....ha ha ha....