I had these aspirations of creating a helpful BUST-esque table of Comparison and Contrast for the various thigh-chafe prevention products, but alas, I am a lazy mofo, and when I couldn't get it right the first time I said WELL FUCK IT and gave up. Because that is the kind of person I am.
Nevertheless: the summer heat is upon us, and unless you're one of those Girls With a Gap, you know what I'm talking about, that space between the upper thighs big enough for fresh breezes to make their way through, then you must heed my words! Or not! Because what works for my thighs may not work for yours!
I have tried a variety of methods over the years, and can tell you that some things are not even worth bothering with: namely, baby powder (useless, clumps, and gives you cancer); plain lotion (absorbs instantly!) and nothing at all (yeah, um, that was a BAD shopping trip to Georgetown, in July). I had just about given up on wearing skirts in the summertime when my grandmother purchased for me out of the J.C. Penney's catalog a pair of pettipants: knee-length nylon bliss, a half-slip split down the middle like charming bloomers. Completely solved the chafe problem, except they got a little hot in the summertime. Also they tended to ride a little high, being designed for the seventy-year-old sensibility, and looked extremely stupid under anything that hit below the bottom of the rib cage. Unless you think a poofy fabric doughnut around the middle is the height of sexfulness. Me, I looked like some sort of Marshmallow'ed Man who had slipped on a skintight Human Suit for the day, so as to pass for an ordinary girl, except the damn thing was too short in the waist, and my Marshmallow Self billowed out unencumbered from the space between the top and bottom pieces.
I made a brief try at bike shorts, but I found that, one, they rode right up between my thighs; two, they were frictive enough to cause my skirt to ride up on my ass until I sported a fetching corduroy belt; and three, they were even hotter than the pettipants, CoolMax be damned.
And then I got knocked up, and none of it fit anyway. I ordered the maternity bike shorts from Decent Exposures only to discover that their conception of belly size was out of line with my reality, and that I loathe the feeling of anything tight over that belly.
So much for the physical methods. It was time to move on to the chemical.
BodyGlide was the first thing I tried; I had to go to a running shop to get it, where I was summarily ignored by counter staff (as a rather obvious non-runner) until I wedged myself in front of a sweaty muscled guy in teeny little running shorts with a big complicated order. Because damned if I was going to wait for some sweaty guy. It comes in a little stick like teeny deodorant, and does, as reported, have a slight odor I am hard-put to describe. Waxy, maybe. It claims to be all-natural, and I believe it, although they don't disclose all the ingredients. It's a thick greasy substance that works on the lubrication principle, and it worked quite well, for the first half of the day (spent around the office doing office-y things). When I headed out into the heat for lunch, it began to absorb into my thighs. Which left them very well-moisturized. And not at all slippery. In fact, they began to catch and drag on each other, and by the end of lunch I had a nice rash going. I reapplied at work and did fine the rest of the day, but it took a couple of days to recuperate totally.
In sum: I'd use it for short jaunts, or around the house/office -- but not so much for a full day's walk in the heat.
Next up was Squeaky Cheeks, a bentonite clay and cornstarch powder with some slippery elm and menthol thrown in for awesomeness. It smelled minty fresh and felt that way, too; I was careful not to get it up in my dainties, but it must be powerful enough to migrate through cotton underpants because within ten minutes my netherlies were tingling. But not in a bad way. Is there a bad way, for netherlies to tingle? Perhaps, if you've been less than judicious with your hot pepper-chopping hands, or if you go right from VapoRub to Nighttime Follies. Anyway.
So it worked pretty well, preventing chafe to approximately the same degree as the BodyGlide, though it felt a lot more pleasant (powdery-dry rather than lubey), and smelled, well, not any less obvious, but somewhat more appealing. It did not bear up exceedingly well to the Tremendous Pressure of the Sweaty Rubbing Thighs once I took it on the road, but it was a lot more pleasant to reapply than the BodyGlide, and the slippery elm must have magical healing properties, because what chafe-rash I did get went away pretty quickly.
It also worked well for soothing hot chafing pits (I know! Can you get over how sexy I am?), and I bet it would be awesome in shoes.
In sum: marginally better for thigh chafe, but very useful all around.