I have the Denso Iridium plugs in my sig and it idles like a new car. I had some advance discounts and they were very little in cost. They are similar to the Motorcraft finewires but have an iridium tip at both ends. They are great for waste spark or COP. They are OEM on Toyota and Lexus cars.
They are gapped to .044 (perfectly, with a protector sleeve). Probably fine to leave it at that, because they are so efficient. I gapped them a bit wider but you have to be VERY careful. The tips can't contact any metal.
You should be fine with a good quality plug. Another thing is when you install the plugs in those crazy positions, you risk cracking one and causing misfires.
Seafoam has a can with a aerosol now, and there are other products like that are required for direct injection. It is very difficult to hydrolock with that can. You are fogging the intake. If you suck down 8oz from a vacuum line, yeah, you got a big problem.