Well I've finally managed to do some more tests and I've had more luck with RIP files. I've found out that for me they only work when using Cloth.

Here are my steps when using RIPs:

1. Hit "Poser List"
2. Go to "Recorded imports"
3. Select import for my figure.

Like I said, this works perfectly on clothing but whenever I select a hair figure I get this message:

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