You need to have ctrl bound to duck and no {blind} tag for space because you need to be spamming ctrl+space in order for it to work, in other words, you need to stand up each time you jump and duck immediately after.
Thanks! However I’m getting more of a horizontal boost instead of a vertical one, maybe it’s because this was done on a later version, because I’m looking at routing with a 2006 GCF version of the game. Cool regardless.
edit:
I managed to do it backwards and drag the barrel up with me from below!