With RC's in which you attempt impossible experiences, it might be hard to imagine what it will really feel like. Your mind hesitates to invent a feeling you've never experienced. So don't just imagine what it would look like to put your finger through your hand. Imagine what it would feel like. I think it would feel like Jello.

It probably depends on the person but I think the nose pinch is the most reliable RC. I think it's because in waking life you can experience both outcomes. You know what it feels like to breathe through your nose and you know what it feels like to have your nose plugged. You don't have to imagine what it would feel like. You can feel the difference and you can be logical about it. It's more about activating awareness and logic than testing reality.

I also like counting fingers. Again, because it doesn't require imagination and it activates the logical part of your brain.