Hi Gamma Goblin
I haven’t got the album to hand, but generally speaking, in my humble opinion a decent dub guitar requires :
Reverb (possibly varying amounts of it rather than the same level of reverb throughout the track). This will give a sense of space / dimension.
Delay / Echo (again using varying amounts of it rather than the same level of delay throughout the track). For example, you could do a 1 step echo on the first chord, then a 4 step echo on the next chord, then a 3 step, then no echo, then back to a 1 step echo etc. Changing the amount of delay on each chord gives the track a more “liquid” feel.
Filter or wah wah. If you have a wah wah pedal then you may as well use it, but if not you can achieve a similar effect by putting the guitar through a Low Pass filter with the resonance turned right up, and then sweeping the cutoff knob backwards and forwards to get the “wah” effect.
Chorus. A big wobbly chorus effect can also add a touch of depth and trippiness to the guitar sound, which seems to work well in dub.
Hope this helps you sir!