His "system" is mostly comprised of stuff he's gathered together over a Long time-frame, going back to the 1990's and earlier.
Some 'bits and pieces" have proven useful to me in practice. I have all his books to date. His concept of the "Field" for example
is reminiscent of the Nordic / Heathen "Web of Wyrd", IMO. He and "friend/s" created the pre-www "z-list" on the Usenet network,
which helped popularize Chaos Magic. So there's a lot of different components he's managed to cobble together into something that
works for "Him"! Some folks think that he takes "animism" to an unprecedented level though? I could not adopt his system as it stands
for myself whole cloth, bits and pieces though for sure. Most practitioner's who have been around for any length of time also seem to
evolve a "practice" which works for "Them", as well, most of the time it can "happen naturally" as a result of adding, subtracting and
pruning various parts of practice over time.
One thing that I have found to be of real value is his "Reclaiming Rite". It has value for anyone practicing magic, new or old, again, IMO.
He recommends it as the First practice for anyone considering his system, and it''s a Solid practice too. There are two versions with only minor
differences, one in "Six Ways", and the other in "Changeling", both pretty equal in results. I've seen other versions/variations on this theme,
but I like this one a Lot. "I" recommend new practitioners perform it daily for at least one Lunar month.
There is even an Annotated Tutorial featuring it here: Aidan Wachter's
Reclaiming Rite!
So, one can get a taste of of his "system" without needing any digital or physical copies of his books!
I'm pretty sure all his books are here in the WF library!