I am rebuilding a transmission for my triumph. What is the easiest way to go about cleaning the case after I get it apart?

Ive seen suggestions to use wheel cleaner and brush/power washer, vinegar, engine degreaser, among others

Any ideas on what would be the easiest that wouldn't leave me with 10 gallons of chemicals I'd have to figure out how to dispose of properly?
Is this something I could a transmission or engine shop into doing? I mean paying them to run it through their parts washer not doing the rebuild.

Contact local transmission rebuilders... ask how much for a clean up. Bring it in... pick it up.

Entertain taking it to a powdercoater. Theyt "blast" clean items before powder coating. Might work for your situation.

If you can find someone near you that does vapor honing, that's a good way to clean cast aluminum.

After draining all the fluids, use a degreaser, or detergent. Let it soak for a few minutes, then blast it with hot water. Alternatively you could take it to a coin operated car wash and do the same.

Be careful using any big boy solvents. I'm not sure if your case is clear coated, but if it is the solvents will peel the clear and then you'll have to re-polish it and re-clear it. Thats a big pain.

I would just hit it with simple green full strength and scrub. How clean does the inside need to be anyway? As long as there's no grit or flaking shellac in there you're good.

Heated hydrosonic tank cleans aluminum.

Accidentally using a big boy solvent was my big concern. I'll call around to a few transmission shops first and if that doesn't work/to expensive I'll pick up some simple green