如何在git中硬删除孤立提交？

我有本地提交不在任何我想删除的分支上。
我不想重定义它们，我真的想要删除它们，并且释放与这些提交相关的所有内容。

I have local commit that are not on any branch that I would like to delete. I don't want to rebase them, I really want to delete them, and loose all the content related to these commit.

是他们的命令这样做吗？

Is their a command to do so ?

到目前为止，我已经尝试过许多人提出的交互式重新分配，但它只是提交，不会删除它们。我也尝试过使用reflog delete，但我无法弄清楚如何将特定的提交ID传递给命令。

So far I've tried interactive rebase as many suggested, but it just move commit around, it doesn't delete them. I've also tried to use reflog delete, but I can't figure out how to pass a specific commit Id to the command.

这里是工作树：

o [master] Commit #6  
|  
o Commit #5  
|  
| o Commit #4  
|/  
o Commit #3  
|  
o Commit #2  
|  
o Commit #1  

我想物理删除提交＃4。

I want to physically delete the commit #4.