Jake, Is there ANY way you can convince her of the usefulness of lube?
It really is not something to use as a "last resort" or only when the wife has "failed". I look at it as more of a sex TOOL than anything else. We use it a lot just because it makes everything feel better; sometimes it helps during foreplay; certain positions cause me to dry up faster, etc. There is no shame in it--I wonder where she got that idea? I mean, if all women waited until they were sopping wet to have sex every time, there would be a LOT less sex going on!
Also I have read here that lube creates arousal in a way that is similar to "tricking" the brain into thinking that it really is aroused and so the sexy feelings come.
Right now, I am 31 wks pregnant and very lubricated ALL the time. Even still, we use it.
If your wife could get past the feeling that she has to be crawling out of her skin with horniness BEFORE you start anything, I bet things would improve immensely. Sometimes I am just not getting that much out of foreplay, although I know that sex will be awesome. That's when the lube comes out and we proceed. Now, I am the HD partner so I am open (and encouraging) this, and I realize your W might not be as open to becoming aroused, but perhaps you could start by seeing if you could persuade her of the benefits of lube? It sounds like she is putting an awful lot of pressure on herself, unecessarily. I know there would be lots of nights that I would have had to beg off sex entirely if I was waiting to become wet naturally. Usually I have no problem but the reasons can range from: I just took a shower, I am breastfeeding a child, the ceiling fan is blowing on me and now my natural lube has been literally blown away, we are taking too long, H is falling asleep during foreplay and I am not becoming aroused, ETC ETC. It is really helpful in these situations.
Good luck and sorry I am no help in the joke department. If you need help in the "being brutally direct with a hint of love" let me know!