I think Dunnes stocks the washing powder - Tesco stocks something too but I can't remember what - possibly the dishwasher tablets.
I have looked into this myself before and the distribution is a bit patchy. Ecover themselves don't have much clue about who stocks it unless the shops informs them. They sent me this link, it is a search of their database for stockists in Ireland but it is very incomplete as it doesn't even have the Ecoshop in Wicklow on it and they are major stockists of Ecover.
[broken link removed][broken link removed]
I would appreciate if you could let me know if you come up with anything especially somewhere in north Dublin / Meath. I'm thinking of also buying the 5litre bottle of shower gel / shampoo as well to avoid regular trips to Boots or wherever to buy toiletries.