SeLinux or Jail

In a forum post from around 2009, i read a discussion and opinion about using jails. My take on that topic was that using a jail is no more secure, indeed even less secure than not using them. At the time, SeLinux was put forward as the best option.

Moving forward to today, I now see we have a jail and that Selinux may break some apps and is therefore left disabled.

And yet, when i google jail vs selinux, i am finding posts suggesting to use both (selinux inside a jail)

So may i ask,

  1. what should we be using where we have client websites on shared hosting?

  2. what does the Webmin>System>Jailkit Jail manager actually do? (when i click on it nothing happens)

Personally, I prefer SeLinux, but more than anything else it is for a situation of taste, comfort and preference. I think I could not make a comparative

SeLinux is better

Has anyone documented the process of using SELINUX with Virtualmin successfully?