Ifly.
True. Only on wet starts which they do not like at all.

Have you downloaded the plans from the AMT website? This is somewhat larer than the average pulsejet but works well. Its worth bearing in mind the hardest part to make is the actual pipe which is usually made from either thin stainless or inconel sheet tig or spot welded. Not easy to do a good job on such thin material.

The hardest part is getting the things going and finding the right mixture for starting. Once found on a good design starting is easy and the scariest/exciting part.

Tony