[Christ]

Yessir, you can stall your engine with a auto-lockup clutch, since there is no "give" anywhere. After testing and such, you'd want to install an RPM switch to automatically unlock them after certain RPM is satisfied, such as just off idle. (1200 RPM, probably.)

Basically, you'd use an MSD Vtec switch, which is RPM activated, normally open. This would ensure that you weren't able to be locked up at anything under whatever "pill" you install. As a manual disable, you'd just have a manual SPST toggle.

Your circuit should look something like this:

12VDC (ignition lead from fuse box) | RPM switch | SPST toggle | "Tee" in the wiring | Blocker diode on each line | A and B inputs on ECU wiring.

You Tee after the switch because you probably don't want to control both solenoids manually, and you need two blocker diodes because if you tee after a single blocker, you're creating a short circuit between the two solenoids, which will power both any time one is powered, throwing a CEL. You may also want a blocker in line w/ the ECU before your wire splice, so the ECU can't detect voltage on that line unless it's openly sending it out.

Total, that should be 4 blocker diodes, 2 that allow power from your manual switch, and two that block power going back to the ECU.