Questions about electrolysis rust removal

Just put together a setup and have done a few tools with success but I was wondering a couple things that I can't seem to find much info on.

If the part is too big for the tub, can you let one end of it stick out of the water and then flip it over and do the other side when you're done or can this cause problems aside from the obvious danger if someone touches it and shorts themselves?

Also has anyone ever dipped an entire intake? I have a cast iron intake that needs some rust removal but I'm not sure how it'll react since the cast iron is more porous than the tools I'm cleaning.

Electrolysis leaves behind a dark grey "crust" that needs to be removed when finished. I cannot see how in the world you could get all of that out of an intake.

I tried a "S" cast iron intake and the results were not impressive. The surface area of the part dictates the current needed, but thats not the hard part. The hard part is the way the rust is removed is almost a "line of sight" with the anode, so you need to position the anode(s) all over the part and even inside the intake for a thorough derusting. I did the entire thing and it came OK good but media blasting would have been much better and I still ended up wire wheeling the gasket surfaces. Check out my acid dipping post, you'll be suprised.
http://www.forabodiesonly.com/mopar/showthread.php?t=346429