What's wrong with you!?

Ben has a thing..... We all do, but Ben's can be annoying. Lately he's enjoying flushing things down the toilet. This isn't exactly a new thing. He had a spin at it about a year ago. We replaced the toilet, bought a lock (much to my mother and grandmothers chargin) and eventually "it" went away.
Ben became much better at using the potty on his own (provided the light was on) and we didn't want to impede this. The lock went away.
Well, each day when Ben comes home from school, his first words are... "I'd like to take a shower please." Strips himself down to his socks, and heads on in.
This week, we've lost two bars of soap to flushing. I talk very seriously to him... No Flushing!
Well.... he got me. I heard a "disturbance" in the bathroom, and caught him flashing thru the bathroom to throw in my hair conditioner and a wash rag. Damn! I run like the wind and dive with both hands into the toilet. Sweet! Now I need a shower.... At that point, I could see something had made it's way down. Ben runs to the bedroom and starts asking to watch his Barney movie. I stand in the doorway with my hands on my hips and yell "What is wrong with you?". Takes me about 6.5 seconds to recall exactly what that is, and I snort at myself. The thing is... and I must know... Does he realize he's misbehaving, and if so, does he realize that there are consequenses? Does autism give you a free ride? What are appropriate punishments? What are the expectations I should have? Is the sheer delight of watching miscellanious items circle the bowl supercede the constant reminders of "don't flush your friends"? I must know, because if given the go ahead, I will ........oh I'll think of something.....
My husband and I are not on speaking terms. He gets home, and I let him know about the "incident". Dumb ass goes in and flushes. HA! I hear him heading downstairs for the wet vac. Comes up stairs, get the toilet water up. Yells out "Where's my tools" You mean the ones you've left in the den for the last 5 months? I drug them downstairs over the weekend in preperation for company. You know you're f*n family. Goes back downstairs with a "think your funny..." To be honest, at that point, I was enjoying myself. Then he takes the toilet off (2x in the last month) and tries getting the object out. After 1/2 hour he gives up and buys a new toilet. Frankly, for 85 bucks, I would have rather seen him try a little harder. Quitter.
Now... I do get that some may think, perhaps, that I should be watching him in the shower to prevent these incidents. Well.... that may be. Thing is, this is the time I've been using to get dinner ready. and I do check frequently. When I'm checking, he's sitting in the shower, soaping himslef up, or playing with his pirate ship... he's a sneaky little turd.
Yesterday during his shower, I put the trash can and plunger on top of the toilet seat figuring if he tries to get in, I'd have a heads up. I went to check on him and he's a stealth sucker. He was flushing as I opened the door. Don't know what or if it was, but as of today.. we can still flush.