After the flame thrower hits the room, you no longer need to clear it. In Fallujah it would have been a nice tool. And in those mud huts in Afghanistan. The only downside is that they really are extremely dangerous to operate.
That would be clearing the room; many buildings have more than one room though... plus, as you illustrate it would give a false sense of security because a room that was hastily cleared via flamethrower could have held a hidy-hole (or closet) that a hostile was hiding in.
The only downside is that they really are extremely dangerous to operate.
More from the incoming small-arms fire of being a bullet-magnet than any deficiency/danger of the flamethrower itself. (IIUC, the fuel is typically akin to diesel and needs more than a typical spark to ignite.)
The flamethrower is an essential weapon for all kinds of close combat where the enemy’s well concealed and dug in like ticks. I tried to get M2A2s for the second attack on Fallujah but was informed by some pompous major at HQMC that the flamethrower violates some treaty now.
We used three types of fuel back when I was a PFC; gasoline, diesel and napalm. Gas gives a huge, billowing flame out to 15-20 meters which is great for enveloping a suspected hideout and really blinds the enemy gunners when you’re executing a road crossing. A skilled operator can actually bounce the stream of flame against a wall to shoot around a corner! Diesel shoots further and is really smoky, also good for obscuring and napalm gets out 40-50 meters or so in a long stream that sticks to your target. Great stuff.
As far as the M-16/M4 family go, we need to replace them as soon as possible. They are far too vulnerable to dirt and debris, too weak for sustained operations, and terrible for rapid clearing and cleaning.
The 5.56 caliber has been tried and found inadequate. In Iraq, it was OK at close engagement but poor at longer ranges and when the enemy had cover. We need a caliber that has good long distance lethality and good penetration of cover, like walls.
We are a nation of firearms expertise - we can do better.