Sexy
Asian
Interracial
Midge-oh, oops - wrong buzzwords.
Most of the good ones have been taken by others.
Focus not only on the buzz words but the words/phrases people shop for. Only if they're applicable of course - some of these terms are regulated and have very specific processes you have to go through to become certified (non-GMO and Kosher are great examples of this). Words like "fresh" are a little risky too if your sauce is made from mash - check with your process authority.
All natural
gluten free
low sodium (anything under ~60 mg/tsp...this is not official, but from what I've seen it's about the threshold)
no artificial colors (or natural colors
no preservatives (or preservative free)
locally sourced
non-GMO
Vegan
Savory
Got a thesaurus? That's a great tool for this sort of thing. Another way of getting it done is to hire a writer who's good at creating blurbs if you're not a good writer yourself. It might flow better. People get very turned off by poor grammar so if writing is not your thing, I'd get a friend to help or bite the bullet and pay someone. This is a marketing tool and thus the face of your brand - if it fails to impress, it could do a lot more harm than good.
One note about the charity driven sauces, and using that in promotion:
I do 3-4 care packages a month to soldiers in harm's way. It's my charity of choice and I do it because I want to do it. I've done it for years now, long before I launched a company. and the only time I ever mention it (other than just now) is when I'm doing a care package drive, or trying to encourage others to do so (on my website I have a page encouraging the cause). I do not use that charity work to sell hot sauce, ever. If a recipient comes back and posts about it, great - that's good karma and will help to promote my brand. But I'm never going to be the one to go to the top of the highest bell tower and shout out that I did or am doing a good deed. That can easily give the wrong impression at worst, and at best it could appear that I'm patting myself on the back for it, thus making more about me than the good cause.
In my opinion it's a very delicate line between doing something for charity and people thinking that you're doing something for charity solely as a promotional tool. From my experience in life some people get very turned off if they think you're only doing something nice to pimp a product or brand.
I'm not saying that's what you're doing - don't get me wrong. But with promotion/marketing perception is everything.
It's 100% your call, and how you handle it can make all the difference - but my belief is that you're better off not mentioning the charity in any promotional materials unless you're promoting that specific charity. E.g. "here's a great cause that I happen to support, and here's links to them if you'd like to contribute, and oh, as an aside a % of proceeds from this product will go to that cause". Or a demure statement on the bottle and product page stating "a % of proceeds from this product support XYZ" while never actively saying anything about it in promotional materials.
But for a promotional mailer it could come off as being in poor taste if handled poorly.
Finally, if you do intend to donate proceeds from a sauce, write down every single penny you make from it and track every single penny you donate, because the IRS has zero tolerance for claiming that without delivering, and from what I've been told it paints a bullseye on you for being audited.
Just opinions of course...good luck with the cards!