Having experienced an engine fire on a PA140 during the climbout for a flight test for a star annual, I can vouch that shutting everything down and then trying to stop the prop BEFORE your max rate ROD is an effective way of slowing the flames down. I had been briefed initially by the CAA pilot who signed me off for the test flying, he was an ex military Empire test pilots school pilot and experienced test pilot for various companies before the CAA. His advice was spot on.
Beating hell out of the mechanic who forgot to tighten the fuel line is a great way of stopping it happening again - as is being selective of the companies you do air tests for...