Well, I’m one of the leading practitioners/trainers in that market.
I didn’t say ladders, I said stairs. And it can help you enter theta, but it won’t necessarily fire off gamma bursts. Theta and gamma are often (not always by any means) mutually exclusive.
Theta with Gamma overlaid is a VERY specific state. People here bat it around as if it is common place. It is anything but. Theta is commonplace. Though it is so deep it takes you doing quite a bit of work to be able to hold it consistently. Gamma is also somewhat common. But the two together are not. That’s why I gave a reliable way of achieving it in my post above. Give it a shot and let me know how it works for you.
Or maybe I will upload a file that you can listen to that will make it far easier. But it is FAR easier still if you have a light and sound machine that is programmable. Due to the frequency following response that lights and sounds enable, it is easy to reliably enter the state.