A member took 1 gram of oral thiopental as a test. He only reported dizziness. 1 gram of oral N can be dangerous. This suggests that oral thiopental is not as strong as oral N. Of course, if the thiopental is pure.
In short, we do not have enough oral thiopental overdose case reports. This seems like a gamble.
IV thiopental works well. 5 grams is enough.