All three of my boys were intrigued by the idea of trade school. We are only dealing with anxiety from being very high strung but I think the anxiety involved in a 4-year bachelors degree had something to do with that. I think my boys found trade school/tech school appealing because they like hands-on stuff, but also because it looked much, much more manageable than a 4 year degree leading to a nebulous future career. They also thought the shortness was appealing, something they had much more confidence that they could do. In the end, they all are (hopefully) going to have a 4-year STEM degree, but none of them, even youngest who agreed to go to engineering school right out of high school, were happy about 4 years of sitting in a classroom. Oldest, who refused to even consider going to college until he was 21 and his brother suggested a tech-type school, suffered through that 4-year degree only because it led to a concrete job at the end. And because he was tired of lugging giant cast iron boilers up basement stairs and nearly lost an eye when a pipe fitting exploded. His current job requires that he go to a trade school every year to either maintain or upgrade certificates. This year, he did 2 2-week stints at school that he was truly excited about (he is 30 now). One was a high voltage safety class, the other an advanced welding class. We got pictures and excited texts once the first week of classroom was over and he was into the second hands-on part. For him, this is the perfect structure - two weeks long, only one week in the classroom, then some really cool hands-on stuff.
I think the idea of having a small business of some sort is a good one. Youngest has a friend who does that. He doesn't make a living at it, but he makes the equivalent of a part-time job, I think, and it is something he enjoys.
I am not dealing with Asperger, though, so take everything I say with a grain of salt. I am just very familiar with the school-hating-peter-pan thing. Anxiety was half the problem and an inborn wish to be working towards a specific, doable goal, preferably one that didn't require sitting still in a classroom, was the other half, in our case.
PS - Youngest and middle one have worked as a tech for an engineering company. In youngest's case, it was internships during his engineering degree. In middle one's case, he began with a short internship and then started a small consulting business and worked for several companies at once, cobbling together a full time job out of it. He used contacts from the internship to do this. In both cases, their job was tinkering with things. They used the milling machine to mill parts for test fixtures, assembled parts to be tested, ran the 3-D printer (which required a bit of tinkering), and generally hung out in the lab/shop area doing small jobs. Another school-hating friend who under duress managed to get a 4-year degree (in something more like 6 years and involving 3 different colleges) and now works full time as a technician for a small start-up company. The trick is to work for a tiny company where you will get to do more things, rather than a big, established company where there is a large hierarchy and many employees and each person does a specific piece of a job for a long time.