It's lag based bedrock breaking but you lag your client instead of the server. In case you have never heard of lag based bedrock breaking, here is a video about it.
You can click this link to see how to use the mod.
Basically when you press a keybind, it delays a couple types of packets from being sent to the server until you release the keybind. So the server does not know what you are doing until you release the keybind.
You will need an efficiency 5 diamond pickaxe or better, some pistons, and some redstone torches. Haste is not required. May or may not work on modded servers. Definitely works in singleplayer or vanilla servers.