Blocking Chimney Flue

Hi all

Any advice on beat way to block chimney flue with insulation?

I’ve a bit of insulation in the attic and thought I might use it to block the flue at the bottom and see what difference it might make.

I know that to do it properly I should cap the chimney and fill with loose EPS balls. But for the moment I thought I could ram some of this up - like the chimney sheep.

Should I put it in a plastic bag before shoving it up?

Appreciate any advice (though I know not to light a fire). Thank you.

Inflate a football at the bottom and fill with concrete.

Thanks.
I’ve rock wool and a lot of threads - it’s hard to separate out what needs to be done.

best advice I’ve seen is block it with rockwool at the bottom and cap it at the top. My chimney stacks are central so not worried about insulation per se throughout the length of the stack.

just wondering the process with stuffing the bottom with rock wool. Plastic bag or not?

thabks all.