It's waxy at Clynelish because they don't clean the waxy/fatty deposits out of the pipework. Iirc they did once and lost the waxy nature, so now they never do.
Bearing in mind there are only 4 irish distilleries. Bushmills is a triple distilled malt and isn't waxy. Cooley is double distilled malt and neither is that, and Killbeggan is still young. Midleton whiskey can have an oily character but i'm not sure if it would be described as waxy. Perhaps occasionally. It's the SPS (single pot still) whiskies that can be oily so that would suggest it was due to the unmalted barley. But having said that many Scottish malts are oily and/or waxy.
I've just realised i can not add anything to this Irish whiskey discussion.