Does he postulate a system that Aspies can run in their mind, at the same time as observing the nonverbal cues to flirting? It seems to me "doing both at once"--observing and running a logical system--would be difficult for an Aspie, as we have very limited space to work with in social interaction. In other words, we're good at one thing at a time.
Funnily enough, the only decent dating advice I've ever seen was from the movie "Hitch" - Funny to me, anyway, because I expected it to be one of those cheesy "He thought he knew the rules of love, but finds love has no rules" kinds of movies. I liked them because the rules weren't manipulative, didn't involve picking up on subtle social signals (with the exception of the "fiddling with keys after a date means she doesn't want to go inside just yet" rule), and actually involved using your own personality rather than inventing a "suave" personality. I also liked that they were fairly systemic, rather than being "fluffy" and emotional.
Here's my interpretation of them - I'm paraphrasing, so I might not have things exactly right. Also, the advice was specific to when you're interested in someone you already know and associate with, so it doesn't really help with finding new people, or going up to strangers.
* Work with what you have - an introvert is just as interesting as an extrovert, but a fraud can be spotted a mile away.
* Before asking for a date, make sure that you have recently made yourself stand out in some unique way. For instance (and this is my own hypothetical example), if you're interested in a work colleague, and you're a good cook, bring a cake or another snacky thing in to work for your colleagues to share. That way you're already on his/her mind in a positive way before you ask.
* When you're trying to impress someone, remember you also have to be "passed" by their friends. In specific terms, make sure you spend as much time talking to and listening to their friends as you do with the person themselves.
* When choosing a place for a date, make sure you avoid the usual cliches, and pick somewhere emphasizing that you have been paying attention to what they are interested in.
* If you go out to do something, make sure you pay attention to the event so you will have something to talk about. For instance, if you see a movie, make sure you're actually following the plot of the movie closely, rather than thinking about the fact that you're on a date.
I think that was all the basics - it's hard to paraphrase, because most of the "rules" were specific to the relationship in the movie, rather than general advice...
I haven't read the Groovy Druid thing - shall have to track it down...