Autoreleasepool is out of your control- you can't do it in ASOC. Memory management is handled by the framework. Why exactly do you think you need autoreleasepool? Applescript is single threaded, and you'd have to use Objective-C code if you want to try to kick off another threaded process, but it can't be an Applescript/ASOC process, only pure Obj-C.
See this post for additional discussion about it: http://macscripter.net/viewtopic.php?id=41359 Shane Stanley is very knowledgeable on ASOC, read his posts.