The style is not my usual - but the first thing that struck me was that I had heard a similar effect with a 'blendable' reverb tank, where you can mix varying amounts of direct (dry) signal - and pure reverb. The more you dialed out the dry signal from the mix, the reverb went off in a really spaced out / self perpetuating direction. About 75% pure reverb tank - and 25% dry guitar signal produced ( accidentally for me ! ) a very similar effect. Failing that, it sounds like a short delay, into a long reverb.
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A simple / cost effective solution might be to borrow an Electro-Harmonix 'Holy Grail' Reverb pedal , and switch the selector to " Flerb " - very 'trippy' indeed ... 8)