Is capable of opening channels to those in hellish places encouraging mediators of late (12)

I believe the answer is:

spiritualism

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'capable of opening channels to those in hellish places encouraging mediators of late' is the definition.
I can't judge whether this defines the answer.

'is' is the wordplay.
I cannot really see how this works, but
'is' is within the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in the Irish Times.

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