There have been a number of threads about Halon,
here is one, you can find others by doing a little searching.
Cliff notes version, Halon works, but it is best in a closed space. No residue, no cleanup. Pretty much outlawed (new production, IIRC) due to ozone issues. Not too good to breathe.
Good luck.
Would I carry one----Yes.
BTY, 37 years in the fire service.
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."