The question is, why do Your mufflers need cleaning to begin with.
Carbs set up to rich, to much oil in Your fuel mix, not running Your equipment WOT?!
I have found that the few mufflers I opened either had no deposits needing cleaned, or they had fatty carbon build up which got off with break cleaner solution and a scrubbing.
No accid, no fire - although, those were split open mufflers!