I know *how* to do it, I just can't do it

But I have a sneaking suspicion... dragonuk44, did you already have the gun when you went to search for the dynamite or did you trade for the gun *afterwards*, i.e. after evading the monster a second time and before going back to the locked door to blow it up?
Because I *think* the way the guy on the video walkthrough managed to get through the second time without even encountering the monster has something to do with the gun. See, I think it's like this: When you already have the gun, you can a) shoot the Others and b) there's no smoke monster on the way back to the hatch. If you don't have the gun and trade for it later, the way back to the hatch becomes a lot more difficult because there's Smokie coming after you.
I don't know if this is true; it's just a suspicion I have. All walkthroughs I've consulted mention the smoke monster on the way back to the hatch - they also trade for the gun later in the game. Walkthroughs that mention trading for the gun *before* going for the dynamite don't mention the monster on the way back and give no hints whatsoever on how to evade it

Hm. If this proves to be correct, this might be the best reason ever to re-start this episode.