As I indicated in my review of The Silk Stocking Murders, I think Berkeley was MUCH better in his next book, The Poisoned Chocolates Case. Written in 1929, it avoids some of the pitfalls encountered in the earlier book, and it boasts a much more ingenious solution. In fact, it boasts six ingenious solutions.
I reviewed The Poisoned Chocolates Case a couple of years ago. You'll find my posted review and information about the book at the link.